Energy storage management system of distributed solar photovoltaic system

Abstract

The invention discloses an energy storage management system of a distributed solar photovoltaic system, which belongs to the technical field of solar photovoltaic energy storage management and comprises a master controller, a photovoltaic power station, an inverter, an energy storage converter, an energy storage battery and electrical equipment. The master controller integrates a plurality of functional modules, collects and analyzes power data monitored and calculated by the module, and constructs a prediction model; the charging and discharging time period judgment and charging control module divides time periods according to a power difference value and optimizes a charging process; the discharge management and power control module determines a discharge mode by integrating the electric quantity, and reduces the cost by combining electricity price regulation and control; the monitoring and early warning module monitors production and consumption deviation and triggers manual regulation and control when the deviation is abnormal; through cooperative work of the modules, accurate energy supply and demand prediction and matching are realized, charge and discharge control of an energy storage battery is optimized, the economical efficiency and stability of the system are improved, and the problems of unreasonable charge and discharge control and insufficient electricity price utilization in energy storage management of an existing distributed solar photovoltaic system are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar photovoltaic energy storage management, and in particular relates to an energy storage management system for a distributed solar photovoltaic system. Background Art

[0002] Distributed solar photovoltaic systems are increasingly being used in solar photovoltaic energy storage management. As energy transition progresses, these systems, as a clean, renewable energy source, are providing power to numerous industrial plants and users. However, these systems face numerous challenges in their actual operation.

[0003] It is difficult to determine the reasonable charging and discharging power in the charge and discharge control of energy storage batteries; the difference in electricity prices in different time periods of the power grid is not fully utilized, and an effective discharge control strategy cannot be formulated in combination with the electricity price period division; for this reason, we propose a distributed solar photovoltaic system energy storage management system. Summary of the Invention

[0004] The object of the present invention is to provide an energy storage management system for a distributed solar photovoltaic system to solve the problems raised in the above background technology.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solutions: an energy storage management system for a distributed solar photovoltaic system, comprising: a main controller, a photovoltaic power station, an inverter, an energy storage converter, an energy storage battery, and electrical equipment;

[0006] The main controller integrates an acquisition and analysis module, a charge and discharge period judgment and charging control module, a discharge management and power control module, and a monitoring and early warning module;

[0007] Collection and analysis module: divides the detection time period, calculates the detection power generation rate and detection power consumption rate of each detection period, builds a power generation and consumption prediction model, and analyzes the detection power generation rate and detection power consumption rate of each detection time period on the day based on this model;

[0008] Charge and discharge period judgment and charging control module: According to the detection period's corresponding power generation rate and power consumption rate, it is divided into balancing, charging or discharging periods. During the charging period, the charging power is analyzed and the charging process is controlled;

[0009] Discharge management and power control module: Analyzes the available power and power demand of the corresponding discharge period, as well as the total power required and total power to be discharged corresponding to the subsequent charging period, and determines the discharge mode of each discharge period based on this;

[0010] Monitoring and early warning module: collects and analyzes the production and consumption deviation values during the monitoring period, and determines whether the deviation is abnormal. If it is abnormal, the duration is recorded. When the early warning duration threshold is reached, a command is sent to the personnel terminal to trigger manual control of the charging and discharging strategy.

[0011] Preferably, the specific process of the acquisition and analysis module calculating the detection power generation rate and the detection power consumption rate of each detection period is as follows:

[0012] Divide the daily time in the factory into several detection periods. For each detection period, obtain the corresponding photovoltaic power station power generation and the real-time load power of the factory at each moment in the detection period;

[0013] Calculate the average power generation rate of the photovoltaic power station and the real-time load power of the plant area during the detection period, as well as the standard deviation, to obtain the detection average rate, detection error, detection average rate, and detection error.

[0014] By assigning different weight coefficients to the average inspection rate and the inspection error, the average inspection rate and the inspection error are multiplied by the corresponding weight coefficients and then added together to obtain the inspection rate.

[0015] By assigning different weight coefficients to the average detection power consumption rate and the standard detection power consumption difference, the average detection power consumption rate and the standard detection power consumption difference are multiplied by the corresponding weight coefficients and then added together to obtain the detection power consumption rate.

[0016] Preferably, the acquisition and analysis module constructs a power generation and consumption prediction model, and the specific process of analyzing the detection power generation rate and the detection power consumption rate in each detection time period of the day is as follows:

[0017] Collect historical data from the past three months, covering the photovoltaic power station power generation rate, factory power consumption rate, and weather data at different test time periods every day from Monday to Sunday. Weather data includes: light intensity, temperature, and cloud cover.

[0018] The collected historical data is divided into a training set, a validation set, and a test set according to a preset ratio, and a convolutional neural network is used for training, validation, and testing to obtain a power consumption prediction model.

[0019] For daily energy storage management within the factory, the weather data for each inspection time period provided by the meteorological department and the information about the day of the week are input into the power generation and consumption prediction model, and the inspection power generation rate and inspection power consumption rate corresponding to each inspection time period of the day are output.

[0020] Preferably, the specific working process of the charge and discharge period judgment and charging control module is:

[0021] For each detection period of the day, the power generation rate and the power consumption rate are subtracted to obtain the power generation and consumption difference rate, and a balanced power consumption interval is preset. If the power generation and consumption difference rate is within the preset balanced power consumption interval, the monitoring period is marked as a balanced period.

[0022] If the power consumption difference rate is greater than the upper limit of the balanced power consumption range, the detection period will be marked as a charging period;

[0023] If the power consumption difference rate is less than the lower limit of the balanced power consumption interval, the detection period will be marked as a discharge period;

[0024] For each charging period, obtain the current remaining power SD of the energy storage battery, the rated power PE of the energy storage battery, the maximum allowable charging power PC of the energy storage battery, and the safe charging power threshold SC;

[0025] When the current remaining capacity SD of the energy storage battery is less than the safe charging capacity threshold SC, the formula is used: Get the optimal charging power PJ, where SDmax is the maximum storage capacity of the energy storage battery, and min() is the minimum value function, that is, select the smaller value from the two values in the brackets;

[0026] Obtain the corresponding power consumption difference rate during the charging period and compare it with the optimal charging power. If the power consumption difference rate is greater than or equal to the optimal charging power, the optimal charging power is used as the charging power for the energy storage battery. At this time, the photovoltaic power station charges the energy storage battery at the optimal charging power through the energy storage converter;

[0027] If the production-consumption difference rate is less than the optimal charging power, the energy storage battery is charged using the production-consumption difference rate as the charging power of the energy storage battery;

[0028] When the remaining power of the energy storage battery is greater than or equal to the safe charging power threshold, charging stops.

[0029] Preferably, the specific process of the discharge management and power control module analyzing the available power and the required power of the corresponding period of the discharge period and the total power to be required and the total power to be discharged corresponding to the subsequent charging period is as follows:

[0030] For each discharge period, calculate the energy consumption difference rate corresponding to each charging period after the discharge period and mark it as CHi; use the formula: The amount of electricity QW expected to be charged into the energy storage battery in the future charging period, the amount of electricity QDi available for discharge in the energy storage battery during the discharge period, and the total amount of electricity expected to be available in subsequent discharge periods are obtained, which are recorded as the total amount of electricity to be discharged QCZ; where f is the preset discharge efficiency coefficient, i is the number of the charging period, i = 1, 2, ..., m; n is the total number of charging periods after the current discharge period, and Ti is the duration corresponding to each detection period;

[0031] Subtract the power consumption rate and power generation rate corresponding to the discharge period to obtain the power consumption difference rate HCa, using the formula: The total amount of electricity demanded in the future discharge period is obtained and recorded as the total amount of electricity to be required QXZ; where a is the number of the discharge period, a = 1, 2, ..., k; k is the total number of future discharge periods starting from the current discharge period;

[0032] Using the formula: Obtain the available electricity at the start of the discharge period, denoted as the available electricity QKa for the period; and the required electricity for the discharge period, denoted as the required electricity QXa for the period; where h is the number of charging periods before the discharge period a.

[0033] Preferably, the specific process for the discharge management and power control module to determine the discharge mode for each discharge period is as follows:

[0034] For each discharge period, obtain the total electricity to be discharged QCZ, the total electricity required QXZ corresponding to the discharge period, and the available electricity QKa and required electricity QXa for each discharge period with this discharge period as the starting period.

[0035] If QCZ ≥ QXZ and QKa ≥ QXa for each discharge period, then mark this discharge period and subsequent discharge periods as the energy storage battery discharge periods.

[0036] If QCZ < QXZ, or QKa < QXa for the discharge period appears, then perform time-of-use electricity price division on the discharge period and perform discharge regulation according to the time-of-use electricity price corresponding to the discharge period.

[0037] Preferably, the specific process for performing discharge regulation according to the time-of-use electricity price corresponding to the discharge period is as follows:

[0038] Calculate the average electricity price corresponding to each detection period according to the electricity price of the power grid in each period, and denote it as the detected time electricity price; set three time-of-use electricity price periods, namely the peak period electricity price, the flat period electricity price, and the valley period electricity price.

[0039] Each time-of-use electricity price period corresponds to an electricity price range. By matching the detected time electricity price corresponding to each discharge period with the electricity price ranges corresponding to all time-of-use electricity price periods, output the time-of-use electricity price period to which each discharge period belongs.

[0040] If it is in the peak period electricity price and QKa < QXa for the discharge period corresponding to this peak period electricity price, then mark this discharge period as the regulation period.

[0041] Regulate the discharge of each regulation period in reverse order of time.

[0042] Preferably, the specific process for regulating the discharge of each regulation period in reverse order of time is as follows:

[0043] For the first regulation period, subtract the available electricity QKa corresponding to the regulation period from the required electricity QXa corresponding to the regulation period, and then divide by the discharge efficiency coefficient f to obtain the lack of electricity for the period.

[0044] Starting from the time closest to the regulation period, for the discharge periods marked as valley electricity prices before the regulation period, the power generated by the discharge periods according to the corresponding detection power rates will be stored in the energy storage battery in order from the nearest to the furthest time, until the stored power generation is greater than or equal to the power shortage in the period;

[0045] If the amount of electricity generated during the discharge period marked as valley electricity price cannot meet the electricity shortage during the regulation period, the grid will be used to charge the energy storage battery until the amount of electricity stored in the energy storage battery can meet the electricity shortage during the period.

[0046] After completing the regulation of the first regulation period, for the subsequent regulation periods, the power shortage is calculated in the same way. Under the premise of ensuring that the power allocation results of the previous regulation period are not affected, the above operation of using the power of the valley electricity price discharge period to supplement and charge the grid is repeated;

[0047] The discharge period of the reserved power used to supplement the regulation period is marked as the grid power supply period. During the grid power supply period, the grid supplementary power supply is used to ensure the power supply of the factory area;

[0048] The above-mentioned method of controlling the power consumption during the peak electricity price control period is marked as the electricity price peak-shaving control method; for the flat electricity price, the electricity price peak-shaving control method is similarly used to perform power allocation operations on the flat electricity price.

[0049] Preferably, for each discharge period, if discharging is performed through the energy storage battery, the discharge process is:

[0050] Obtain the current remaining power SD of the energy storage battery, the rated power PE of the energy storage battery, and the maximum allowable discharge power PD of the energy storage battery; and use the formula: Get the maximum discharge power PF;

[0051] Obtain the corresponding consumption-production differential rate HCa during the discharge period. If the consumption-production differential rate is less than or equal to the maximum discharge power, use the consumption-production differential rate as the discharge power of the energy storage battery. At this time, the energy storage battery supplies power to the plant loads through the energy storage converter at this discharge power.

[0052] If the consumption difference rate is greater than the maximum discharge power, the energy storage battery will be discharged at the maximum discharge power.

[0053] Preferably, the specific working process of the monitoring and early warning module is:

[0054] For each inspection period of the factory on the same day, several inspection points are set up to collect the actual inspection power generation rate of the photovoltaic power station corresponding to each inspection point and the actual inspection power consumption rate of the factory. The actual inspection power generation rate and the actual inspection power consumption rate are subtracted to obtain the actual production and consumption difference rate;

[0055] For each detection point, the actual production and consumption difference rate corresponding to the detection point is subtracted from the production and consumption difference rate output by the production and consumption power prediction model at the detection point, and the absolute value is taken to obtain the production and consumption deviation value; if the production and consumption deviation value is greater than the corresponding threshold, the detection point time is taken as the starting time, and the duration that the production and consumption deviation value is greater than the corresponding threshold is recorded, which is recorded as the warning duration. If the warning duration is greater than the corresponding threshold, a warning instruction is generated and sent to the personnel terminal, and the personnel terminal dispatches staff to manually adjust the charging and discharging strategy in each detection period.

[0056] Compared with the prior art, the present invention has the following beneficial effects:

[0057] (1) The energy storage management system and system of the distributed solar photovoltaic system monitors and calculates the power generation power of the photovoltaic power station and the real-time load power of the plant area in each time period through the collection and analysis module, builds a production and consumption power prediction model, predicts the detection power generation rate and detection power consumption rate of each detection period of the day, and divides each detection period of the day into charging, discharging and balancing periods based on this; calculates the optimal charging power during the charging period and flexibly adjusts it according to the production and consumption difference rate to avoid damage to the battery caused by overcharging and extend the battery life; at the same time, ensures that charging is carried out efficiently and fully utilizes photovoltaic power generation; during the discharge period, calculates the maximum discharge power and flexibly adjusts the discharge power in combination with the production and consumption difference rate of the discharge period; protects the energy storage battery, avoids damage to the battery due to excessive discharge and extends the battery life.

[0058] (2) The energy storage management system and system of the distributed solar photovoltaic system, the discharge management and power control module comprehensively calculates the relevant power during the discharge period and determines the reasonable discharge mode; introduces the electricity price period division mechanism, and when the electricity price is on the peak period and the power is insufficient, the electricity price peak regulation method is used to preferentially use the remaining power during the valley period to replenish the energy storage battery, and the insufficient power is charged by the power grid. This method effectively avoids the high price of electricity during the peak period, reasonably utilizes the low price electricity, significantly reduces the electricity cost, and improves the economy of the system.

[0059] (3) The energy storage management system and system of the distributed solar photovoltaic system, the monitoring and early warning module collects actual production and consumption data by setting detection points, and obtains the production and consumption deviation value by comparing with the prediction model; once the deviation is abnormal and the duration reaches the early warning time, it sends an instruction to the personnel terminal to trigger the manual control of the charging and discharging strategy; this mechanism can capture the abnormal situation of energy production and consumption in time, prevent the problem from worsening, reduce the loss caused to the production and operation of the factory due to unstable energy supply, and ensure the stable operation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 It is a structural block diagram of the present invention;

[0061] Figure 2 It is a flowchart of the present invention;

[0062] Figure 3 This is the power allocation diagram of the present invention. DETAILED DESCRIPTION

[0063] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0064] Example 1

[0065] See also Figure 1-3 , the present invention provides an energy storage management system for a distributed solar photovoltaic system, comprising: a main controller, a photovoltaic power station, an inverter, an energy storage converter, an energy storage battery and electrical equipment;

[0066] The photovoltaic power station is responsible for converting solar energy into direct current (DC), which can be converted into alternating current (AC) via inverters to power the electrical equipment within the factory. It can also be stored in storage batteries via energy storage inverters. The storage batteries can then power the electrical equipment within the factory via energy storage converters. The main controller is used to regulate the operation of the entire system.

[0067] The main controller integrates the acquisition and analysis module, the charge and discharge period judgment and charging control module, the discharge management and power control module, and the monitoring and early warning module;

[0068] The acquisition and analysis module divides the detection period, calculates the detection power generation rate and detection power consumption rate of each detection period, and builds a power generation and consumption prediction model based on weather data. Then, combined with the weather data of the day, it outputs the detection power generation rate and detection power consumption rate corresponding to each detection period of the day. The specific process is as follows:

[0069] Current sensors, voltage sensors, and smart meters are installed at the distributed photovoltaic project implementation site to collect real-time data on the photovoltaic power station's generated power, the plant's real-time load power, and the grid's real-time electricity price. The collected data is pre-processed to remove outliers and noise interference, and then sent to the data analysis and prediction unit.

[0070] Divide the daily time in the factory into several detection periods. For each detection period, obtain the corresponding photovoltaic power station power generation and the real-time load power of the factory at each moment in the detection period;

[0071] Calculate the average power generation rate of the photovoltaic power station and the real-time load power of the plant area during the detection period, as well as the standard deviation, to obtain the detection average rate, detection error, detection average rate, and detection error.

[0072] By assigning different weight coefficients to the average detection rate and the detection error, the average detection rate and the detection error are multiplied by the corresponding weight coefficients and then added together to obtain the detection power generation rate. The larger the detection power generation rate, the greater the power generated by the photovoltaic power station during the detection period.

[0073] By assigning different weight coefficients to the average inspection consumption rate and the standard inspection consumption difference, the average inspection consumption rate and the standard inspection consumption difference are multiplied by the corresponding weight coefficients and then added together to obtain the inspection power consumption rate. The larger the inspection power consumption rate, the greater the power load power consumed by the electrical equipment in the factory during the inspection period.

[0074] Collect historical data from the past three months, covering the photovoltaic power station's power generation rate, the factory's power consumption rate, and weather data at different test time periods every day from Monday to Sunday. Weather data includes: light intensity, temperature, cloud cover, etc.

[0075] The above-mentioned collected historical data is divided into a training set, a validation set, and a test set according to a preset ratio, and a convolutional neural network is used for training, validation, and testing to obtain a production and consumption power prediction model. When establishing the production and consumption power prediction model, the neural network is trained using the training set to obtain a preliminary production and consumption power prediction model. The Adam optimizer can be used during training, with the learning rate set to 0.001 and a preset number of iterations. Subsequently, the learning rate, number of iterations, and other hyperparameters are adjusted using the validation set. Finally, the accuracy of the prediction results is evaluated using the test set. When the accuracy probability of the prediction result is greater than the preset accuracy probability, the model is output to obtain the production and consumption power prediction model.

[0076] For daily energy storage management within the factory, the weather data for each inspection time period provided by the meteorological department and the information about the day of the week are input into the power generation and consumption prediction model, and the inspection power generation rate and inspection power consumption rate corresponding to each inspection time period of the day are output.

[0077] It should be noted that the average value and standard deviation of the photovoltaic power station's power generation and the plant's real-time load power in each time period are analyzed to obtain the average detection rate, detection error, detection consumption average rate, and detection error, and the detection power generation rate and detection power consumption rate are calculated by reasonably allocating weight coefficients; these indicators can intuitively reflect the power generation capacity of the photovoltaic power station and the power consumption load of the plant's electrical equipment, helping the system to have a more comprehensive understanding of the energy supply and demand situation; and use convolutional neural networks to construct a power generation and consumption prediction model to predict the detection power generation rate and detection power consumption rate in each detection period of the day, so as to reasonably arrange the charging and discharging of energy storage batteries, reduce energy waste, and improve energy utilization efficiency.

[0078] The charge and discharge period judgment and charging control module divides each detection period into balancing, charging or discharging period according to the detection power generation rate and detection power consumption rate corresponding to the detection period. During the charging period, the charging power is analyzed and the charging process is controlled. The specific process is as follows:

[0079] For each detection period of the day, the power generation rate and the power consumption rate are subtracted to obtain the power generation and consumption difference rate, and a balanced power consumption interval is preset. If the power generation and consumption difference rate is within the preset balanced power consumption interval, the monitoring period is marked as a balanced period.

[0080] If the power generation and consumption difference rate is greater than the upper limit of the balanced power consumption interval, it means that the power generation rate is significantly higher than the power consumption rate. In this case, the detection period is marked as a charging period. If the power generation and consumption difference rate is less than the lower limit of the balanced power consumption interval, it means that the power generation rate is lower than the power consumption rate. In this case, the detection period is marked as a discharging period.

[0081] For each charging period, obtain the current remaining power SD of the energy storage battery, the rated power PE of the energy storage battery, the maximum allowable charging power PC of the energy storage battery, and the safe charging power threshold SC;

[0082] When the current remaining capacity SD of the energy storage battery is less than the safe charging capacity threshold SC, the formula is used: Get the optimal charging power PJ, where SDmax is the maximum storage capacity of the energy storage battery, and min() is the minimum value function, that is, select the smaller value from the two values in the brackets;

[0083] Obtain the corresponding power consumption difference rate during the charging period and compare it with the optimal charging power. If the power consumption difference rate is greater than or equal to the optimal charging power, the optimal charging power is used as the charging power for the energy storage battery. At this time, the photovoltaic power station charges the energy storage battery at the optimal charging power through the energy storage converter;

[0084] If the production-consumption difference rate is less than the optimal charging power, the energy storage battery is charged using the production-consumption difference rate as the charging power of the energy storage battery;

[0085] When the current remaining power of the energy storage battery is greater than or equal to the safe charging power threshold, charging is stopped; the excess power generated during the charging period can be negotiated with the local power grid company to integrate the excess photovoltaic power generation into the public power grid for sale.

[0086] It should be noted that by comparing the difference between the power generation rate and the power consumption rate during the detection period, combined with the preset balancing power consumption interval, the balancing, charging and discharging periods can be accurately divided; this facilitates full utilization of photovoltaic power generation, charging and storing energy when there is excess power generation, and discharging and supplying energy when there is insufficient power generation, thereby improving energy self-sufficiency and reducing dependence on the power grid;

[0087] By calculating the optimal charging power and comparing the power consumption difference rate with the optimal charging power, the charging power can be flexibly adjusted. This not only avoids damage to the battery due to overcharging, prolongs the battery life, but also ensures efficient charging.

[0088] When the energy storage battery reaches the safe charging threshold, charging stops and the excess generated electricity is incorporated into the public power grid for sale; this not only ensures battery safety, but also realizes the secondary utilization of energy and increases economic benefits.

[0089] The discharge management and power control module analyzes the available power and power demand during the discharge period, as well as the total power required and total power to be discharged during the subsequent charging period. Based on this, it determines the discharge mode for each discharge period. At the same time, it regulates the discharge power according to the energy storage battery status and the power demand of the factory area. The specific process is as follows:

[0090] For each discharge period, calculate the energy consumption difference rate corresponding to each charging period after the discharge period and mark it as CHi; use the formula: The amount of electricity QW expected to be charged into the energy storage battery in the future charging period, the amount of electricity QDi available for discharge in the energy storage battery during the discharge period, and the total amount of electricity expected to be available in the subsequent discharge period are obtained, which are recorded as the total amount of electricity to be discharged QCZ; where f is the preset discharge efficiency coefficient, i is the number of the charging period, i = 1, 2, ..., m; m is the total number of charging periods after the current discharge period, and Ti is the duration corresponding to each detection period;

[0091] Subtract the power consumption rate and power generation rate corresponding to the discharge period to obtain the power consumption difference rate HCa, using the formula: The total amount of electricity demanded in the future discharge period is obtained and recorded as the total amount of electricity to be required QXZ; where a is the number of the discharge period, a = 1, 2, ..., k; k is the total number of future discharge periods starting from the current discharge period;

[0092] Using the formula: Obtain the available power at the beginning of the discharge period and record it as the available power during the period QKa; and the required power during the discharge period and record it as the required power during the period QXa; where h is the number of charging periods before the discharge period a;

[0093] For each discharge period, obtain the total amount of electricity to be discharged QCZ, the total amount of electricity to be required QXZ corresponding to the discharge period, and the available electricity QKa and the required electricity QXa corresponding to each discharge period starting from the discharge period;

[0094] If QCZ≥QXZ, and QKa≥QXa corresponding to each discharge period, then the discharge period and subsequent discharge periods are marked as energy storage battery discharge periods;

[0095] If QCZ < QXZ, or QKa < QXa corresponding to the discharge period appears, the electricity price period of the discharge period is divided, and the discharge is regulated according to the electricity price period corresponding to the discharge period. Specifically:

[0096] According to the electricity price of the power grid in each period, calculate the average electricity price corresponding to each detection period and record it as the detected time electricity price; set three electricity price periods, namely peak period electricity price, flat period electricity price and valley period electricity price;

[0097] Each electricity price period corresponds to an electricity price interval. By matching the detected time electricity price corresponding to each discharge period with the electricity price intervals corresponding to all electricity price periods, the electricity price period to which each discharge period belongs is output;

[0098] If it is in the peak period electricity price and QKa < QXa corresponding to the discharge period of the peak period electricity price, mark the discharge period as the regulated period; where the regulated period is for the energy storage battery to discharge;

[0099] In reverse order of time, regulate the discharge of each regulated period in turn, such as Figure 3 , the specific process is:

[0100] When regulating, the subsequent regulated periods are carried out on the basis of satisfying the previous regulated periods; for the first regulated period, subtract the available electricity QKa of the period from the required electricity QXa of the period corresponding to the regulated period and then divide by the discharge efficiency coefficient f to obtain the lack of electricity in the period;

[0101] Starting from the one closest to the regulated period in time, for the discharge periods marked as valley period electricity price before the regulated period, in the order from near to far in time, successively deposit the electricity generated according to the corresponding detected power generation rate of these discharge periods into the energy storage battery instead of supplying it to the plant electricity consumption until the stored electricity is greater than or equal to the lack of electricity in the period;

[0102] If the electricity generated by the discharge period marked as valley period electricity price cannot meet the lack of electricity in the regulated period, at this time, use the power grid to charge the energy storage battery until the stored electricity of the energy storage battery can meet the demand of the lack of electricity in the period;

[0103] After completing the regulation of the first regulated period, for the subsequent regulated periods, first calculate the lack of electricity in the period as well. On the premise of ensuring that the electricity distribution result of the previously regulated periods is not affected, repeat the above operations of using the electricity of the valley period electricity price discharge periods for supplement and grid charging; that is: preferentially use the electricity generated by the valley period electricity price discharge periods to supplement the energy storage battery, and the insufficient part is supplemented by grid charging to ensure that each regulated period can meet the electricity demand;

[0104] The discharge period of the reserved power used to supplement the regulation period is marked as the grid power supply period. During the grid power supply period, the grid supplementary power supply is used to ensure the power supply of the factory area;

[0105] The above-mentioned method of regulating electricity quantity during the peak electricity price regulation period is marked as the electricity price peak-shaving regulation method; for the flat electricity price, the electricity price peak-shaving regulation method is similarly used to allocate electricity quantity during the flat electricity price period.

[0106] For each discharge period, if the discharge is carried out through the energy storage battery, the discharge process is:

[0107] Obtain the current remaining power SD of the energy storage battery, the rated power PE of the energy storage battery, and the maximum allowable discharge power PD of the energy storage battery; and use the formula: Get the maximum discharge power PF;

[0108] Obtain the corresponding power consumption differential rate HCa during the discharge period. If the power consumption differential rate is less than or equal to the maximum discharge power, the power consumption differential rate is used as the discharge power of the energy storage battery. At this time, the energy storage battery uses the discharge power to supply power to the plant load through the energy storage converter to compensate for the insufficient photovoltaic power generation.

[0109] If the power consumption difference rate is greater than the maximum discharge power, the energy storage battery will be discharged at the maximum discharge power. In this state, it means that the power demand of the factory exceeds the maximum discharge capacity that the energy storage battery can currently provide. At the same time, the factory also needs to supplement the remaining power from the power grid to ensure normal production operations of the factory.

[0110] It should be noted that the discharge mode of each discharge period is accurately determined by comprehensively calculating the available power in the corresponding period of the discharge period, the power demand in the period, the total power required in the subsequent charging period, and the total power to be discharged. When the total power to be discharged is sufficient to meet future power demand and the available power in each period can meet the demand of the current period, the energy storage battery is continuously discharged to fully utilize the stored power, reduce the purchase of electricity from the power grid, improve energy self-sufficiency, and reduce electricity costs.

[0111] A price-period division mechanism is introduced, dividing the discharge period into peak, flat, and valley periods based on the electricity prices of the power grid during different periods. During peak periods with insufficient electricity, these periods are marked as regulation periods and the peak-off regulation method is implemented. The surplus electricity during valley-period discharge periods is preferentially used to replenish the energy storage battery, with the remaining electricity being charged by the grid. This method effectively avoids high-priced electricity during peak periods, rationally utilizes low-priced electricity, significantly reduces electricity costs, and improves the economic efficiency of the system.

[0112] The maximum discharge power is calculated based on the current remaining power of the energy storage battery, rated power and maximum allowable discharge power, and the discharge power is flexibly adjusted in combination with the consumption-production difference rate during the discharge period; when the consumption-production difference rate does not exceed the maximum discharge power, the consumption-production difference rate is used as the discharge power to ensure a stable power supply to the factory; when the consumption-production difference rate exceeds the maximum discharge power, although the discharge is carried out at the maximum discharge power, the remaining power is replenished from the power grid in a timely manner to ensure that the production and operation of the factory are not affected, while protecting the energy storage battery, avoiding damage to the battery due to excessive discharge, and extending the battery life.

[0113] The monitoring and early warning module collects and analyzes the production and consumption deviation values during the monitoring period, and determines whether the deviation is abnormal. If it is abnormal, it records the duration. When the early warning duration threshold is reached, a command is sent to the personnel terminal to trigger the manual control of the charge and discharge strategy. The specific process is as follows:

[0114] For each inspection period of the factory on the same day, several inspection points are set up to collect the actual inspection power generation rate of the photovoltaic power station corresponding to each inspection point and the actual inspection power consumption rate of the factory. The actual inspection power generation rate and the actual inspection power consumption rate are subtracted to obtain the actual production and consumption difference rate;

[0115] For each detection point, the actual production and consumption difference rate corresponding to the detection point is subtracted from the production and consumption difference rate output by the production and consumption power prediction model at the detection point, and the absolute value is taken to obtain the production and consumption deviation value; a production and consumption deviation value threshold is preset. If the production and consumption deviation value is greater than the corresponding threshold, the detection point time is used as the starting time, and the duration for which the production and consumption deviation value is greater than the corresponding threshold is recorded, which is recorded as the warning duration. A warning duration threshold is preset. If the warning duration is greater than the corresponding threshold, a warning instruction is generated and sent to the personnel terminal. The inspection staff at the personnel terminal manually adjust the charging and discharging strategies in each detection period.

[0116] It should be noted that the actual production and consumption difference rate is calculated and compared with the output value of the production and consumption power prediction model to obtain the production and consumption deviation value. Once the production and consumption deviation value exceeds the threshold and the duration reaches the warning time, an instruction is sent to the personnel terminal. In this way, it is easy to capture abnormal conditions of energy production and consumption, prevent problems from worsening, and reduce losses to plant production operations caused by unstable energy supply.

[0117] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An energy storage management system for a distributed solar photovoltaic system, comprising: A main controller, a photovoltaic power station, an inverter, an energy storage converter, an energy storage battery, and electrical equipment, characterized by: The main controller integrates an acquisition and analysis module, a charge and discharge period judgment and charging control module, a discharge management and power control module, and a monitoring and early warning module; Collection and analysis module: divides the detection time period, calculates the detection power generation rate and detection power consumption rate of each detection period, builds a power generation and consumption prediction model, and analyzes the detection power generation rate and detection power consumption rate of each detection time period on the day based on this model; Charge and discharge period judgment and charging control module: According to the detection period's corresponding power generation rate and power consumption rate, it is divided into balancing, charging or discharging periods. During the charging period, the charging power is analyzed and the charging process is controlled; Discharge management and power control module: Analyzes the available power and power demand of the corresponding discharge period, as well as the total power required and total power to be discharged of the subsequent charging period, and determines the discharge mode of each discharge period based on this; Monitoring and early warning module: collects and analyzes the production and consumption deviation values during the monitoring period, and determines whether the deviation is abnormal. If it is abnormal, the duration is recorded. When the early warning duration threshold is reached, a command is sent to the personnel terminal to trigger manual control of the charging and discharging strategy.

2. The energy storage management system of a distributed solar photovoltaic system according to claim 1, characterized in that: The specific process of the acquisition and analysis module calculating the detection power generation rate and detection power consumption rate of each detection period is as follows: Divide the daily time in the factory into several detection periods. For each detection period, obtain the corresponding photovoltaic power station power generation and the real-time load power of the factory at each moment in the detection period; Calculate the average power generation rate of the photovoltaic power station and the real-time load power of the plant area during the detection period, as well as the standard deviation, to obtain the detection average rate, detection error, detection average rate, and detection error. By assigning different weight coefficients to the average inspection rate and the inspection error, the average inspection rate and the inspection error are multiplied by the corresponding weight coefficients and then added together to obtain the inspection rate. By assigning different weight coefficients to the average detection power consumption rate and the standard detection power consumption difference, the average detection power consumption rate and the standard detection power consumption difference are multiplied by the corresponding weight coefficients and then added together to obtain the detection power consumption rate.

3. The energy storage management system of a distributed solar photovoltaic system according to claim 2, characterized in that: The acquisition and analysis module builds a power generation and consumption prediction model, and the specific process of analyzing the power generation rate and power consumption rate in each detection time period of the day is as follows: Collect historical data from the past three months, covering the photovoltaic power station power generation rate, factory power consumption rate, and weather data at different test time periods every day from Monday to Sunday. Weather data includes: light intensity, temperature, and cloud cover. The collected historical data is divided into a training set, a validation set, and a test set according to a preset ratio, and a convolutional neural network is used for training, validation, and testing to obtain a power consumption prediction model. For daily energy storage management within the factory, the weather data for each inspection time period provided by the meteorological department and the information about the day to which the day belongs are input into the power generation and consumption prediction model, and the inspection power generation rate and inspection power consumption rate corresponding to each inspection time period of the day are output.

4. The energy storage management system of a distributed solar photovoltaic system according to claim 3, characterized in that: The specific working process of the charge and discharge period judgment and charging control module is as follows: For each detection period of the day, calculate the difference between the power generation rate and the power consumption rate within the detection period to obtain the production - consumption difference rate. Preset a balanced power consumption range. If the production - consumption difference rate is within the preset balanced power consumption range, mark this monitoring period as a balanced period; If the production - consumption difference rate is greater than the upper limit of the balanced power consumption range, mark the detection period as a charging period; If the production - consumption difference rate is less than the lower limit of the balanced power consumption range, mark the detection period as a discharging period; For each charging period, obtain the current remaining power SD of the energy storage battery, the rated power PE of the energy storage battery, the maximum allowable charging power PC of the energy storage battery, and the safety charging power threshold SC; When the current remaining capacity SD of the energy storage battery is less than the safe charging capacity threshold SC, the formula is used: Get the optimal charging power PJ, where SDmax is the maximum storage capacity of the energy storage battery, and min() is the minimum value function, that is, select the smaller value from the two values in the brackets; Obtain the production - consumption difference rate corresponding to the charging period and compare it with the optimal charging power. If the production - consumption difference rate is greater than or equal to the optimal charging power, use the optimal charging power as the charging power of the energy storage battery. At this time, the photovoltaic power station charges the energy storage battery at the optimal charging power through the energy storage converter; If the production - consumption difference rate is less than the optimal charging power, use the production - consumption difference rate as the charging power of the energy storage battery to charge the energy storage battery; When the current remaining power of the energy storage battery is greater than or equal to the safety charging power threshold, stop charging.

5. The energy storage management system of a distributed solar photovoltaic system according to claim 4, characterized in that: The specific process of the discharging management and power control module analyzing the available power and the required power in the corresponding period of the discharging period, as well as the total required power and the total discharging power to be required in the subsequent charging periods corresponding to the discharging period is as follows: For each discharge period, calculate the energy consumption difference rate corresponding to each charging period after the discharge period and mark it as CHi; use the formula: Obtain the amount of electricity QW expected to be charged into the energy storage battery during the future charging period, the amount of electricity QDi available for discharge from the energy storage battery during the discharge period, and the total amount of electricity expected to be available for subsequent discharge periods, recorded as the total amount of electricity to be discharged QCZ; where f is the preset discharge efficiency coefficient, and i is the number of the charging period, i = 1, 2, ..., m; m is the total number of charging periods after the current discharging period, and Ti is the duration corresponding to each detection period; Difference the power consumption rate and power generation rate corresponding to the discharge period to obtain the power consumption difference rate HCa, using the formula: The total amount of electricity demanded in the future discharge period is obtained and recorded as the total amount of electricity to be required QXZ; where a is the number of the discharge period, a = 1, 2, ..., k; k is the total number of future discharge periods starting from the current discharge period; Using the formula: The available power at the beginning of the discharge period is obtained and recorded as the available power during the period QKa; and the required power during the discharge period is recorded as the required power during the period QXa; where h is the number of charging periods before the discharge period a.

6. The energy storage management system of a distributed solar photovoltaic system according to claim 5, characterized in that: The specific process of the discharging management and power control module determining the discharging mode of each discharging period is as follows: For each discharging period, obtain the total discharging power QCZ, the total required power QXZ corresponding to the discharging period, and the available power QKa and the required power QXa corresponding to each discharging period starting from this discharging period; If QCZ≥QXZ and QKa≥QXa corresponding to each discharging period, mark this discharging period and the subsequent discharging periods as the discharging periods of the energy storage battery; If QCZ < QXZ, or QKa < QXa corresponding to the discharging period appears, divide the discharging period into electricity price periods and perform discharging regulation according to the electricity price periods corresponding to the discharging period.

7. The energy storage management system of a distributed solar photovoltaic system according to claim 6, characterized in that: The specific process of performing discharging regulation according to the electricity price periods corresponding to the discharging period is as follows: According to the electricity price of the power grid in each period, calculate the average electricity price corresponding to each detection period and record it as the detected - time electricity price; set three electricity price periods, namely the peak - period electricity price, the flat - period electricity price, and the valley - period electricity price; Each electricity price period corresponds to an electricity price range. By matching the detected - time electricity price corresponding to each discharging period with the electricity price ranges corresponding to all electricity price periods, output the electricity price period to which each discharging period belongs; If it is in the peak - period electricity price and QKa < QXa corresponding to the discharging period of this peak - period electricity price, mark this discharging period as a regulated period; In reverse chronological order, regulate the discharging of each regulated period in turn.

8. The energy storage management system of a distributed solar photovoltaic system according to claim 7, characterized in that: The specific process of regulating the discharging of each regulated period in turn in reverse chronological order is as follows: For the first regulated period, subtract the available power QKa from the required power QXa corresponding to the regulated period and then divide by the discharging efficiency coefficient f to obtain the lack of power in the period; Starting from the time closest to the regulation period, for the discharge periods marked as valley electricity prices before the regulation period, the power generated by the discharge periods according to the corresponding detection power rates will be stored in the energy storage battery in order from the nearest to the furthest time, until the stored power generation is greater than or equal to the power shortage in the period; If the amount of electricity generated during the discharge period marked as valley electricity price cannot meet the electricity shortage during the regulation period, the grid will be used to charge the energy storage battery until the amount of electricity stored in the energy storage battery can meet the electricity shortage during the period. After completing the regulation of the first regulation period, for the subsequent regulation periods, the power shortage is calculated in the same way. Under the premise of ensuring that the power allocation results of the previous regulation period are not affected, the above operation of using the power of the valley electricity price discharge period to supplement and charge the grid is repeated; The discharge period during which the electricity is used to supplement the regulation period is marked as the grid power supply period. During the grid power supply period, the grid supplementary power supply is used to ensure the power supply of the factory area. The above-mentioned method of controlling the power consumption during the peak electricity price control period is marked as the electricity price peak-shaving control method; for the flat electricity price, the electricity price peak-shaving control method is similarly used to perform power allocation operations on the flat electricity price.

9. The energy storage management system of a distributed solar photovoltaic system according to claim 8, characterized in that: For each discharge period, if the discharge is performed through the energy storage battery, the discharge process is: Obtain the current remaining power SD of the energy storage battery, the rated power PE of the energy storage battery, and the maximum allowable discharge power PD of the energy storage battery; and use the formula: Get the maximum discharge power PF; Obtain the corresponding energy consumption difference rate HCa during the discharge period; if the energy consumption difference rate is less than or equal to the maximum discharge power, use the energy consumption difference rate as the discharge power of the energy storage battery; At this time, the energy storage battery supplies power to the plant loads through the energy storage converter with this discharge power; If the consumption difference rate is greater than the maximum discharge power, the energy storage battery will be discharged at its maximum discharge power.

10. The energy storage management system of a distributed solar photovoltaic system according to claim 2, characterized in that: The specific working process of the monitoring and early warning module is as follows: For each inspection period of the factory on the same day, several inspection points are set up to collect the actual inspection power generation rate of the photovoltaic power station corresponding to each inspection point and the actual inspection power consumption rate of the factory. The actual inspection power generation rate and the actual inspection power consumption rate are subtracted to obtain the actual production and consumption difference rate; For each detection point, the actual production and consumption difference rate corresponding to the detection point is subtracted from the production and consumption difference rate output by the production and consumption power prediction model at the detection point, and the absolute value is taken to obtain the production and consumption deviation value; If the production and consumption deviation value is greater than the corresponding threshold, the detection point time is taken as the starting time, and the duration of the production and consumption deviation value greater than the corresponding threshold is recorded as the warning duration. If the warning duration is greater than the corresponding threshold, a warning instruction is generated and sent to the personnel terminal. The personnel terminal dispatches staff to manually adjust the charging and discharging strategies in each detection period.

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