An energy storage management system for a distributed solar photovoltaic system

Abstract

The application discloses a kind of energy storage management systems of distributed solar photovoltaic system, belong to solar photovoltaic energy storage management technical field, including host computer, photovoltaic power station, inverter, energy storage converter, energy storage battery and electrical equipment;Host computer integrates multiple function modules, acquisition analysis module monitors calculation power data, constructs prediction model;Charging and discharging period judgment and charging control module divides period according to power difference, optimizes charging process;Discharge management and power control module determines discharge mode comprehensively, reduces cost in combination with electricity price regulation and control;Monitoring and early warning module monitors production and consumption deviation, triggers artificial regulation when abnormal;Through the collaborative work of these modules, precise energy supply and demand forecasting and matching are realized, the optimization of energy storage battery charging and discharging control improves the economy and stability of the system, solves the problem of unreasonable charging and discharging control in the existing distributed solar photovoltaic system energy storage management, insufficient use of electricity price.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of solar photovoltaic energy storage management, and particularly relates to a kind of energy storage management systems of distributed solar photovoltaic system. BACKGROUND

[0002] In the aspect of solar photovoltaic energy storage management, the application of distributed solar photovoltaic system is more and more widespread; with the promotion of energy transformation, distributed photovoltaic system as a clean, renewable energy utilization method provides power support for many factories and users; however, the system faces many challenges in actual operation;

[0003] In the aspect of energy storage battery charging and discharging control, it is difficult to determine reasonable charging and discharging power; the difference in power price of power grid at different times is not fully utilized, and effective discharge regulation strategy cannot be formulated combined with power price period division; therefore, we propose a kind of energy storage management system of distributed solar photovoltaic system. SUMMARY

[0004] The purpose of the present application is to provide a kind of energy storage management system of distributed solar photovoltaic system to solve the problems raised in the background art.

[0005] To achieve the above purpose, the present application provides the following technical scheme: a kind of energy storage management system of distributed solar photovoltaic system, comprising: main control unit, photovoltaic power station, inverter, energy storage converter, energy storage battery and electrical equipment;

[0006] The main control unit is integrated with a collection and analysis module, a charging and discharging period judgment and charging control module, a discharge management and power control module, and a monitoring and early warning module.

[0007] The collection and analysis module: divides the detection period, calculates the detection power generation rate and detection power consumption rate of each detection period, constructs a power generation and consumption power prediction model, and analyzes the detection power generation rate and detection power consumption rate of each detection period based on this;

[0008] The charging and discharging period judgment and charging control module: according to the detection power generation rate and detection power consumption rate corresponding to the detection period, it is divided into balance, charging or discharging period, in the charging period, the charging power is analyzed, and the charging process is controlled;

[0009] The discharge management and power control module: analyzes the available power and period demand power of the discharge period corresponding period and the total power to be needed and the total power to be discharged of the subsequent charging period corresponding to the total power to be needed and the total power to be discharged, and determines the discharge mode of each discharge period based on this;

[0010] The monitoring and early warning module: collects and analyzes the monitoring period production and consumption deviation value, and judges whether the deviation is abnormal, if abnormal, records the duration, when the warning duration threshold is reached, sends instructions to the personnel terminal, triggers manual regulation and control of charging and discharging strategy.

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

[0012] The time of the plant area is divided into several detection periods every day, and for each detection period, the photovoltaic power station generation power and the real-time load power of the plant area corresponding to each time in the detection period are obtained;

[0013] The average value and the standard deviation of the photovoltaic power station generation power and the real-time load power of the plant area in the detection period are calculated respectively to obtain the detection generation average rate, the detection generation standard deviation, the detection consumption average rate and the detection consumption standard deviation;

[0014] By assigning different weight coefficients to the detection generation average rate and the detection generation standard deviation, the detection generation average rate and the detection generation standard deviation are multiplied by the corresponding weight coefficients and then added to obtain the detection generation rate;

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

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

[0017] The historical data of the last three months is collected, which covers the detection generation rate of the photovoltaic power station, the detection consumption rate of the plant area, and weather data in different detection periods from Monday to Sunday every day; the weather data includes: light intensity, temperature, and cloud cover;

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

[0019] For the energy storage management in the plant area, the weather data of each detection period of the day provided by the meteorological department is input into the generation and consumption power prediction model together with the day of the week information, and the detection generation rate and the detection consumption rate corresponding to each detection period of the day are output.

[0020] Preferably, the specific working process of the charging and discharging period judgment and charging control module is as follows:

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

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

[0023] If the production-consumption difference rate is less than the lower limit of the balance electricity consumption interval, the detection period is marked as a discharge period;

[0024] For each charging period, 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 are obtained.

[0025] When the current remaining power SD of the energy storage battery is less than the safe charging power threshold SC, the optimal charging power PJ is obtained by using the formula: , wherein SDmax is the maximum storage power of the energy storage battery, and min() is a minimum value function, that is, the smaller value is selected from the two values in the parentheses.

[0026] The corresponding production-consumption difference rate in the charging period is obtained and compared with the optimal charging power. If the production-consumption difference rate is greater than or equal to the optimal charging power, the optimal charging power is used as the charging power of the energy storage battery. At this time, the photovoltaic power station charges the energy storage battery through the energy storage converter at the optimal charging power.

[0027] If the production-consumption difference rate is less than the optimal charging power, the production-consumption difference rate is used as the charging power of the energy storage battery to charge the energy storage battery.

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

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

[0030] For each discharge period, the production-consumption difference rate of each charging period after the discharge period is calculated and marked as CHi. The formula is: , wherein f is a preset discharge efficiency coefficient, i is the label 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 length of each detection period.

[0031] The difference between the detection consumption rate and the detection generation rate of the discharge period is obtained to obtain the consumption-production difference rate HCa. The formula is: , wherein a is the label of the discharge period, a = 1, 2, …, k; k is the total number of future discharge periods after the current discharge period; and the total power demand of the future discharge period is recorded as the total power to be needed QXZ.

[0032] The formula is: obtaining the available power at the beginning of the discharging period and denoted as period available power QKa, and the discharging period demand power denoted as period demand power QXa; wherein h is the number of charging periods before the discharging period a.

[0033] Preferably, the specific process of determining the discharging mode of each discharging period by the discharging management and power control module is as follows:

[0034] For each discharging period, the total discharging required power QXZ and the total discharging available power QCZ corresponding to the discharging period are obtained, as well as the period available power QKa and the period demand power QXa corresponding to each discharging period starting from the discharging period;

[0035] If QCZ≥QXZ and QKa≥QXa corresponding to each discharging period, the discharging period and the subsequent discharging periods are marked as energy storage battery discharging periods;

[0036] If QCZ<QXZ or QKa<QXa corresponding to the discharging period, the discharging period is divided into price periods, and the discharging is regulated according to the price period corresponding to the discharging period.

[0037] Preferably, the specific process of regulating the discharging according to the price period corresponding to the discharging period is as follows:

[0038] According to the price of the power grid in each period, the average price corresponding to each detection period is calculated and denoted as detection time price; three price periods are set, which are peak period price, flat period price and valley period price;

[0039] Each price period corresponds to a price interval, and by matching the detection time price corresponding to each discharging period with the price interval corresponding to all price periods, the price period to which each discharging period belongs is output;

[0040] If it is located in the peak period price and QKa<QXa corresponding to the discharging period of the peak period price, the discharging period is marked as a regulation period;

[0041] According to the time in reverse order, the discharging of each regulation period is regulated in turn.

[0042] Preferably, the specific process of regulating the discharging according to the time in reverse order is as follows:

[0043] For the first regulation period, the period demand power QXa and the period available power QKa corresponding to the regulation period are subtracted and then divided by the discharging efficiency coefficient f to obtain the period lack of power;

[0044] From the time closest to the beginning of the regulation period, for the discharge period marked as valley period electricity price before the regulation period, in the order of time from near to far, the discharge period is stored in the energy storage battery according to the corresponding detection generation rate until the stored power is greater than or equal to the period lack of power.

[0045] If the power generated by the discharge period marked as valley period electricity price cannot meet the period lack of power of the regulation period, the energy storage battery is charged by the power grid until the power stored in the energy storage battery can meet the demand of the period lack of power.

[0046] After the regulation of the first regulation period is completed, for the subsequent regulation period, the period lack of power is also calculated, and under the premise of ensuring that the power distribution results of the previously regulated periods are not affected, the above-mentioned operation of supplementing the power of the discharge period of the valley period electricity price and charging by the power grid is repeated.

[0047] The power reserve is used to supplement the discharge period of the regulation period, which is marked as the power grid power supply period, and the power grid is used to supplement power supply in the power grid power supply period to ensure the power consumption of the factory area.

[0048] The above-mentioned power regulation method for the peak period electricity price regulation period is marked as the peak shaving regulation method; for the flat period electricity price, the peak shaving regulation method is used to perform power distribution operation on the flat period electricity price.

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

[0050] 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 are obtained; and the formula: The maximum discharge power PF is obtained.

[0051] The corresponding consumption difference rate HCa in the discharge period is obtained; if the consumption difference rate is less than or equal to the maximum discharge power, the consumption difference rate is used as the discharge power of the energy storage battery; at this time, the energy storage battery supplies power to the factory area load through the energy storage converter at the discharge power.

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

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

[0054] For each detection period of the factory area on the same day, a plurality of detection points are set, the actual detection generation rate of the photovoltaic power station and the actual detection consumption rate of the factory area corresponding to each detection point are collected, and the actual detection generation rate and the actual detection 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 power prediction model output at the detection point time, 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 value, 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 value is recorded, which is recorded as the warning duration, if the warning duration is greater than the corresponding threshold value, a warning instruction is generated and sent to the personnel terminal, and the personnel terminal dispatches workers to manually control the charging and discharging strategy in each detection period.

[0056] Compared with the prior art, the beneficial effects of the present application are:

[0057] (1), the energy storage management system and system of the distributed solar photovoltaic system, through the monitoring and calculation of the photovoltaic power station power generation power and the real-time load power of the factory area by the acquisition and analysis module, a production and consumption power prediction model is constructed, the detection power generation rate and the detection power consumption rate of each detection period of the day are predicted, and based on this, each detection period of the day is divided into charging, discharging and balancing period; the optimal charging power is calculated in the charging period and is flexibly adjusted according to the production and consumption difference rate, so that the damage to the battery caused by excessive charging is avoided, and the service life of the battery is prolonged; at the same time, the charging is ensured to be efficient, and the photovoltaic power generation is fully utilized; in the discharging period, the maximum discharging power is calculated, and the discharging power is flexibly adjusted in combination with the production and consumption difference rate of the discharging period; the energy storage battery is protected, and the damage to the battery caused by excessive discharging is avoided, and the service life of the battery is prolonged.

[0058] (2), the energy storage management system and system of the distributed solar photovoltaic system, the discharging management and power control module determines the reasonable discharging mode by comprehensively calculating the related electric quantity in the discharging period; the electricity price period division mechanism is introduced, when the peak segment electricity price and the electric quantity are insufficient, the electricity price peak regulation method is used, the remaining electric quantity in the valley segment electricity price discharging period is preferentially used to supplement the energy storage battery, and the insufficient part is charged by the power grid. This way effectively avoids the high-priced electricity in the peak segment, reasonably uses the low-priced electricity, significantly reduces the electricity cost, and improves the system economy.

[0059] (3), the energy storage management system and system of the distributed solar photovoltaic system, the monitoring and warning module acquires the 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 warning duration, an instruction is sent to the personnel terminal, and the manual control charging and discharging strategy is triggered; this mechanism can timely capture the abnormal situation of energy production and consumption, prevent the problem from worsening, reduce the loss caused by unstable energy supply to the production and operation of the factory area, and ensure the stable operation of the system. BRIEF DESCRIPTION OF DRAWINGS

[0060] Fig. 1 The structure diagram of the present application;

[0061] Fig. 2 The flowchart of the present application;

[0062] Fig. 3 The power allocation diagram of the present application. DETAILED DESCRIPTION

[0063] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0064] Embodiment one

[0065] Please refer to Figs. 1-3 The present application provides a kind of energy storage management system of distributed solar photovoltaic system, comprising: main control unit, photovoltaic power station, inverter, energy storage converter, energy storage battery and electrical equipment;

[0066] Photovoltaic power station is responsible for converting solar energy into direct current, which can be converted into alternating current by inverter to supply energy for electrical equipment in the factory area;On the other hand, it can be stored in energy storage battery through energy storage inverter;Energy storage battery can supply energy for electrical equipment in the factory area through energy storage converter;Main control unit is used to regulate the operation of the whole system;

[0067] The main control unit is integrated with a collection and analysis module, a charging and discharging period judgment and charging control module, a discharging management and power control module, and a monitoring and early warning module;

[0068] The collection and analysis module divides the detection period, calculates the detection power generation rate and detection power consumption rate of each detection period, and constructs a power generation and consumption power prediction model according to weather data, then outputs the detection power generation rate and detection power consumption rate corresponding to each detection time period of the day combined with the weather data of the day, the specific process is as follows:

[0069] Install current sensor, voltage sensor and smart meter etc. in the implementation site of distributed photovoltaic project;It is used to collect photovoltaic power station power, real-time load power of factory area and real-time electricity price of power grid in real time;The collected data information is preprocessed to remove outliers and noise interference, and then sent to data analysis and prediction unit;

[0070] The time of the factory area every day is divided into several detection periods, and for each detection time period, the photovoltaic power station power and the real-time load power of the factory area corresponding to each time in the detection time period are obtained;

[0071] The average value and standard deviation of photovoltaic power station power and real-time load power of the factory area in the detection time period are calculated respectively, and the detection power generation rate, detection power generation standard deviation, detection power consumption rate and detection power consumption standard deviation are obtained;

[0072] The detection power generation rate is obtained by multiplying the detection power generation average and the detection power generation deviation by different weight coefficients and then adding them together; the greater the detection power generation rate, the greater the power generated by the photovoltaic power station during the detection period;

[0073] The detection power consumption rate is obtained by multiplying the detection power consumption average and the detection power consumption deviation by different weight coefficients and then adding them together; the greater the detection power consumption rate, the greater the power consumption load of the electrical equipment in the factory area during the detection period;

[0074] The historical data collected in the last three months covers the detection power generation rate of the photovoltaic power station, the detection power consumption rate of the factory area, and weather data for different detection time periods from Monday to Sunday every day; the weather data includes: light intensity, temperature, cloud cover, etc.

[0075] The historical data collected above is divided into a training set, a validation set, and a test set according to a preset proportion, 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 training set is used to train the neural network to obtain a preliminary production and consumption power prediction model; the Adam optimizer can be used during training, with a learning rate of 0.001 and a preset number of iterations; then the validation set is used to adjust the learning rate, the number of iterations, and other hyperparameters; finally, the test set is used to evaluate the accuracy of the prediction results; when the accuracy probability of the prediction results is greater than a preset accuracy probability, the model is output, and the production and consumption power prediction model is obtained.

[0076] For the energy storage management of the factory area every day, the weather data of each detection time period provided by the meteorological department on the same day is input into the production and consumption power prediction model together with the day of the week information, and the detection power generation rate and the detection power consumption rate corresponding to each detection time period on the same day are output.

[0077] It should be noted that the average and standard deviation of the photovoltaic power station power generation and the real-time load power of the factory area in each period are analyzed to obtain the detection power generation average, the detection power generation deviation, the detection power consumption average, and the detection power consumption deviation, and the detection power generation rate and the detection power consumption rate are calculated by reasonably allocating weight coefficients; these indicators can directly reflect the power generation capacity of the photovoltaic power station and the power consumption load of the electrical equipment in the factory area, helping the system to better understand the energy supply and demand situation; and a production and consumption power prediction model is constructed using a convolutional neural network to predict the detection power generation rate and the detection power consumption rate of each detection time period on the same day, which facilitates the reasonable arrangement of the charging and discharging of the energy storage battery, reduces energy waste, and improves energy utilization efficiency.

[0078] The charge and discharge period judgment and charge control module divides each detection period into a balance period, a charging period or a discharging period according to the detection power generation rate and the detection power consumption rate corresponding to the detection period. In 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 difference between the detection power generation rate and the detection power consumption rate in the detection period is obtained to obtain a production and consumption difference rate. A balance power consumption interval is preset. If the production and consumption difference rate is within the preset balance power consumption interval, the monitoring period is marked as a balance period.

[0080] If the production and consumption difference rate is greater than the upper limit of the balance power consumption interval, it indicates that the detection power generation rate is significantly higher than the detection power consumption rate. At this time, the detection period is marked as a charging period. If the production and consumption difference rate is less than the lower limit of the balance power consumption interval, it indicates that the detection power generation rate is lower than the detection power consumption rate. At this time, the detection period is marked as a discharging period.

[0081] For each charging period, 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 are obtained.

[0082] When the current remaining power SD of the energy storage battery is less than the safe charging power threshold SC, the optimal charging power PJ is obtained by using the formula: Where SDmax is the maximum storage power of the energy storage battery, and min() is a minimum value function, that is, the smaller value is selected from the two values in the parentheses.

[0083] The production and consumption difference rate corresponding to the charging period is obtained and compared with the optimal charging power. If the production and consumption difference rate is greater than or equal to the optimal charging power, the optimal charging power is used as the charging power of the energy storage battery. At this time, the photovoltaic power station charges the energy storage battery through the energy storage converter at the optimal charging power.

[0084] If the production and consumption difference rate is less than the optimal charging power, the production and consumption difference rate is used as the charging power of the energy storage battery to charge 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, the charging is stopped. At this time, the excess power generation of the charging period can be negotiated with the local power grid company, and the excess photovoltaic power generation is integrated into the public power grid for sale.

[0086] It should be noted that by comparing the difference between the detection power generation rate and the detection power consumption rate of the detection period, and combining the preset balance power consumption interval, the balance, charging and discharging periods are accurately divided. It is convenient to fully utilize photovoltaic power generation, charge energy storage when power generation is surplus, discharge power when power generation is insufficient, improve energy self-sufficiency rate, and reduce dependence on the power grid.

[0087] By calculating the optimal charging power; comparing the production and consumption difference rate with the optimal charging power, the charging power is flexibly adjusted; both avoiding damage to the battery due to overcharging and prolonging the service life of the battery, and ensuring efficient charging process;

[0088] When the energy storage battery power reaches the safe charging power threshold, charging is stopped, and the excess power is sold into the public grid; this not only ensures the safety of the battery, 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 demand power of the period corresponding to the discharge period, as well as the total power to be discharged and the total power to be discharged corresponding to the subsequent charging period, and determines the discharge mode of each discharge period based on this; at the same time, according to the state of the energy storage battery and the demand for power consumption in the factory area, the discharge power is regulated, and the specific process is:

[0090] For each discharge period, calculate the production and consumption difference rate of each charging period after the discharge period, and mark it as CHi; using the formula: Get the amount of power QW that the future charging period is expected to charge into the energy storage battery, the amount of power QDi that the energy storage battery can be used for discharging in this discharge period, and the total power that can be used for subsequent discharge periods, marked as total power to be discharged QCZ; where f is a preset discharge efficiency coefficient, i is the label of the charging period, i = 1, 2, …, m; m is the total number of charging periods after the current discharge period; Ti is the length of each detection period;

[0091] Subtract the detection consumption rate from the detection power generation rate corresponding to the discharge period to get the consumption and production difference rate HCa, using the formula: Get the total power demand of the future discharge period, marked as total power to be needed QXZ; where a is the label 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: Get the available power at the start of the discharge period, and mark it as period available power QKa; and the demand power of the discharge period, marked as period demand power QXa; where h is the number of charging periods before the discharge period a;

[0093] For each discharge period, get the total power to be discharged QCZ, the total power to be needed QXZ corresponding to the discharge period, and the period available power QKa and the period demand power QXa corresponding to each discharge period starting from the discharge period;

[0094] If QCZ≥QXZ, and QKa≥QXa for each discharge period, then mark the discharge period and subsequent discharge periods as energy storage battery discharge periods;

[0095] If QCZ < QXZ, or QKa < QXa when the discharge period corresponding discharge period appears, the discharge period is divided into electricity price period, 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, the average electricity price corresponding to each detection period is calculated, and is recorded as the detection time electricity price; three electricity price periods are set, which are 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 detection time electricity price corresponding to each discharge period with the electricity price interval corresponding to all electricity price periods, the electricity price period to which each discharge period belongs is output;

[0098] If it is located in the peak period electricity price and the QKa of the discharge period corresponding to the peak period electricity price is less than QXa, the discharge period is marked as a regulation period; wherein the regulation period is the discharge of the energy storage battery;

[0099] According to the time in reverse order, the discharge of each regulation period is regulated in turn, such as Fig. 3 , the specific process is:

[0100] When regulating, the subsequent regulation period is carried out on the basis of meeting the previous regulation period; for the first regulation period, the period demand QXa corresponding to the regulation period is subtracted from the period available QKa and then divided by the discharge efficiency coefficient f to obtain the period lack of electricity;

[0101] From the nearest time to the regulation period, for the discharge period marked as the valley period electricity price before the regulation period, in the order from near to far, these discharge periods are stored in the energy storage battery according to the generated power of the corresponding detection power generation rate, instead of being supplied to the plant power consumption, until the stored power is greater than or equal to the period lack of electricity;

[0102] If the power generated by the discharge period marked as the valley period electricity price cannot meet the period lack of electricity of the regulation period, the power grid is used to charge the energy storage battery until the amount of electricity stored in the energy storage battery can meet the demand of the period lack of electricity;

[0103] After completing the regulation of the first regulation period, for the subsequent regulation period, the period lack of electricity is also calculated, and on the premise of ensuring not to affect the power distribution results of the previously regulated period, the above-mentioned operation of supplementing the valley period electricity price discharge period and the power grid charging is repeated; that is, the power of the valley period electricity price discharge period is used to supplement the energy storage battery, and the insufficient part is supplemented by the power grid charging, to ensure that each regulation period can meet the power demand;

[0104] The electric quantity reserve is used to supplement the discharge period of the regulation period, which is marked as the grid power supply period, and the grid power supply is used to ensure the power supply of the plant area during the grid power supply period;

[0105] The above electric quantity regulation method for the peak period is marked as the peak shaving regulation method. The flat section electricity price is also regulated by the peak shaving regulation method.

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

[0107] The current remaining electric quantity 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 are obtained, and the formula: The maximum discharge power PF is obtained.

[0108] The corresponding consumption-production difference rate HCa in the discharge period is obtained. If the consumption-production difference rate is less than or equal to the maximum discharge power, the consumption-production difference rate is used as the discharge power of the energy storage battery. At this time, the energy storage battery supplies power to the plant area load through the energy storage converter at the discharge power to make up for the insufficient photovoltaic power.

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

[0110] It should be noted that the discharge mode of each discharge period is accurately determined by comprehensively calculating the available electric quantity of the discharge period, the demand electric quantity of the period, the total electric quantity to be charged and the total electric quantity to be discharged in the subsequent charging period. When the total electric quantity to be discharged is sufficient to meet the future power demand, and the available electric quantity of each period can meet the demand of the current period, the energy storage battery is continuously discharged, the stored electric energy is fully utilized, the grid power purchase is reduced, the energy self-sufficiency rate is improved, and the power cost is reduced.

[0111] The price period division mechanism is introduced, and the discharge period is divided into peak, flat, and valley price periods according to the different time period prices of the grid. When the peak price and the electric quantity are insufficient, it is marked as a regulation period and the peak shaving regulation method is implemented. The remaining electric quantity of the valley price discharge period is used to supplement the energy storage battery, and the insufficient part is charged by the grid. This method effectively avoids high-priced electricity in the peak period, reasonably uses low-priced electricity, significantly reduces the power cost, and improves the system economy.

[0112] The maximum discharge power is calculated based on the current remaining charge, rated power, and maximum allowable discharge power of the energy storage battery. The discharge power is then flexibly adjusted in conjunction with the power consumption difference rate during the discharge period. When the power consumption difference rate does not exceed the maximum discharge power, the discharge power is based on the power consumption difference rate to ensure a stable power supply to the plant area. When the power consumption difference rate exceeds the maximum discharge power, although the discharge is based on the maximum discharge power, the remaining power is replenished from the grid in a timely manner to ensure that the plant's production and operation are not affected. At the same time, the energy storage battery is protected from over-discharge, which can damage the battery and extend its service 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 abnormal, the duration is recorded. When the early warning duration threshold is reached, a command is sent to the personnel terminal to trigger manual adjustment of the charging and discharging strategy. The specific process is as follows:

[0114] For each testing period of the day, several testing points are set up, and the actual power generation rate of the photovoltaic power station and the actual power consumption rate of the factory area are collected at each testing point. The difference between the actual power generation rate and the actual power consumption rate is calculated to obtain the actual power generation-consumption difference rate.

[0115] For each detection point, the difference between the actual power consumption difference rate corresponding to the detection point and the power consumption difference rate output by the power consumption prediction model at the detection point time is calculated and the absolute value is taken to obtain the power consumption deviation value. A preset power consumption deviation value threshold is set. If the power consumption deviation value is greater than the corresponding threshold, the duration for which the power consumption deviation value is greater than the corresponding threshold is recorded, starting from the detection point time. This duration is recorded as the warning duration. A preset warning duration threshold is set. If the warning duration is greater than the corresponding threshold, a warning instruction is generated and sent to the personnel terminal. The personnel terminal inspection staff 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 detect abnormal situations in energy production and consumption, prevent the problem from worsening, and reduce the losses caused by unstable energy supply to the plant's production and operation.

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

Claims

1. An energy storage management system for a distributed solar photovoltaic system, comprising: The master controller, photovoltaic power station, inverter, energy storage converter, energy storage battery and electrical equipment are characterized in that: The master controller is integrated with a collection and analysis module, a charging and discharging period judgment and charging control module, a discharging management and power control module, and a monitoring and early warning module; The collection and analysis module: divides the detection period, calculates the detection power generation rate and detection power consumption rate of each detection period, constructs a power generation and consumption power prediction model, and analyzes the detection power generation rate and detection power consumption rate of each detection period based on this; The charging and discharging period judgment and charging control module: according to the detection power generation rate and detection power consumption rate corresponding to the detection period, it is divided into balance, charging or discharging period, in the charging period, the charging power is analyzed, and the charging process is controlled; The discharging management and power control module: analyzes the available power and period demand power of the discharging period corresponding period and the total power to be needed and the total power to be discharged corresponding to the subsequent charging period, and determines the discharging mode of each discharging period based on this; The specific process of analyzing the available power and period demand power of the discharging period corresponding period and the total power to be needed and the total power to be discharged corresponding to the subsequent charging period is: For each discharge period, calculate the power consumption difference rate for each subsequent charging period and label it CHi; using the formula: The expected charge QW to be added to the energy storage battery during the future charging period, the amount of charge QDi that the energy storage battery can discharge during the current discharge period, and the total amount of charge expected to be available for subsequent discharge periods are obtained and denoted as the total charge 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, Ti is the duration of each detection period, and SDi is the remaining charge of the energy storage battery in the i-th charging period. The difference between the detected power consumption rate and the detected power generation rate corresponding to the discharge period is calculated to obtain the power consumption difference rate HCa, which is obtained using the formula: The total electricity demand for future discharge periods is obtained and denoted as the total demand QXZ; where a is the label of the discharge period, a=1,2,...,k; and k is the total number of future discharge periods starting from the current discharge period. Using the formula: The available power at the start of the discharge period is obtained and denoted as the available power QKa; and the power required during the discharge period is denoted as the power required during the period QXa; where h is the number of charging periods before the discharge period a. The monitoring and early warning module: collects and analyzes the monitoring period power generation and consumption deviation value, and judges whether the deviation is abnormal, if it is abnormal, records the duration, when the warning duration threshold is reached, sends instructions to the personnel terminal, triggers manual regulation and control of the charging and discharging strategy.

2. The energy storage management system of a distributed solar PV system of claim 1, wherein: The specific process of the collection and analysis module calculating the detection power generation rate and detection power consumption rate of each detection period is: Divide the time in the factory area every day into several detection periods, for each detection time period, obtain the photovoltaic power station power generation power and real-time load power of the factory area corresponding to each time in the detection time period; Calculate the average value and standard deviation of the photovoltaic power station power generation power and real-time load power of the factory area in the detection time period respectively to obtain the detection power generation rate, detection power generation deviation, detection power consumption rate and detection power consumption deviation; By assigning different weight coefficients to the detection power generation rate and detection power generation deviation, the detection power generation rate and detection power generation deviation are multiplied by the corresponding weight coefficients and then added to obtain the detection power generation rate; By assigning different weight coefficients to the detection power consumption rate and detection power consumption deviation, the detection power consumption rate and detection power consumption deviation are multiplied by the corresponding weight coefficients and then added to obtain the detection power consumption rate.

3. The energy storage management system of a distributed solar PV system of claim 2, wherein: The specific process of the collection and analysis module constructing a power generation and consumption power prediction model and analyzing the detection power generation rate and detection power consumption rate of each detection time period on the same day is: Collect historical data of the last three months, which covers the detection power generation rate of the photovoltaic power station, the detection power consumption rate of the factory area, and weather data in different detection time periods from Monday to Sunday every day; Weather data includes: light intensity, temperature, cloud cover; By dividing the above collected historical data into training set, validation set and test set according to the preset proportion, and using convolutional neural network for training, validation and testing, the power generation and consumption power prediction model is obtained; For the energy storage management in the factory area, input the weather data of each detection time period provided by the meteorological department on the same day into the power generation and consumption power prediction model together with the day of the week information, and output the detection power generation rate and detection power consumption rate corresponding to each detection time period on the same day.

4. The energy storage management system of a distributed solar PV system of claim 3, wherein: The specific working process of the charging and discharging period judgment and charging control module is: For each detection period of the day, the difference between the detection period's generation and consumption power is calculated to obtain the production and consumption difference rate. A preset balance power consumption interval is set. If the production and consumption difference rate is within the preset balance power consumption interval, the monitoring period is marked as a balance period. If the production and consumption difference rate is greater than the upper limit of the balance power consumption interval, the detection period is marked as a charging period. If the production and consumption difference rate is less than the lower limit of the balance power consumption interval, the detection period is marked as a discharging period. For each charging period, the current remaining capacity 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 capacity threshold SC are obtained. When the current remaining capacity SD of the energy storage battery is less than the safe charging capacity threshold SC, the optimal charging power PJ is obtained by using the formula: , where SDmax is the maximum storage capacity of the energy storage battery, and min() is a minimum function that selects the smaller value from the two values in the parentheses. The corresponding production and consumption difference rate in the charging period is obtained and compared with the optimal charging power. If the production and consumption difference rate is greater than or equal to the optimal charging power, the optimal charging power is used as the charging power of the energy storage battery. At this time, the photovoltaic power station charges the energy storage battery through the energy storage converter at the optimal charging power. If the production and consumption difference rate is less than the optimal charging power, the production and consumption difference rate is used as the charging power of the energy storage battery to charge the energy storage battery. When the current remaining capacity of the energy storage battery is greater than or equal to the safe charging capacity threshold, the charging is stopped.

5. The energy storage management system of a distributed solar PV system of claim 4, wherein: The specific process of the discharge management and power control module to determine the discharge mode of each discharging period is as follows: For each discharging period, the total discharging capacity QCZ, the total required capacity QXZ, the period available capacity QKa, and the period demand capacity QXa corresponding to each discharging period are obtained. If QCZ≥QXZ and QKa≥QXa for each discharging period, the discharging period and the subsequent discharging periods are marked as energy storage battery discharging periods. If QCZ<QXZ or QKa<QXa for a discharging period, the discharging period is divided into price periods, and the discharging is regulated according to the price period corresponding to the discharging period.

6. The energy storage management system of a distributed solar PV system of claim 5, wherein: The specific process of regulating discharging according to the price period corresponding to the discharging period is as follows: According to the price of the power grid in each period, the average price of each detection period is calculated and recorded as the detection time price. Three price periods are set, namely the peak period price, the flat period price, and the valley period price. Each price period corresponds to a price interval. By matching the detection time price of each discharging period with the price interval corresponding to all price periods, the price period to which each discharging period belongs is output. If it is located in the peak period price and the QKa of the discharging period corresponding to the peak period price is less than QXa, the discharging period is marked as a regulation period. According to the time in reverse order, the discharging of each regulation period is regulated in turn.

7. The energy storage management system of a distributed solar PV system of claim 6, wherein: The specific process of regulating discharging according to the time in reverse order is as follows: For the first regulation period, the difference between the period demand capacity QXa and the period available capacity QKa corresponding to the regulation period is calculated and then divided by the discharge efficiency coefficient f to obtain the period lack of capacity. From the time closest to the beginning of the regulation period, for the discharge period marked as valley period electricity price before the regulation period, in the order of time from near to far, the discharge period is stored in the energy storage battery according to the corresponding detection generation rate until the stored power is greater than or equal to the period lack of power; If the power generated by the discharge period marked as valley period electricity price cannot meet the period lack of power of the regulation period, the grid is used to charge the energy storage battery until the power stored in the energy storage battery can meet the demand of the period lack of power; After the regulation of the first regulation period is completed, for the subsequent regulation period, the period lack of power is also calculated, and the above-mentioned operation of supplementing the power of the discharge period of the valley period electricity price and the grid charging is repeated on the premise of not affecting the power distribution results of the previously regulated period. The discharge period whose power is used to supplement the regulation period is marked as the grid power supply period, and the grid is used to supplement power supply in the grid power supply period to ensure the power consumption of the factory area; The above-mentioned power regulation method for the peak period electricity price regulation period is marked as the peak shaving regulation method; for the flat period electricity price, the peak shaving regulation method is used to perform power distribution operation on the flat period electricity price.

8. The energy storage management system of a distributed solar PV system of claim 7, wherein: For each discharge period, if the discharge is performed through the energy storage battery, the discharge process is: The current residual capacity SD of the energy storage battery, the rated power PE of the energy storage battery, and the maximum allowable discharging power PD of the energy storage battery are acquired, and the maximum discharging power PF is obtained by using a formula: ​ Obtain the corresponding HCa of the discharge period; If the HCa is less than or equal to the maximum discharge power, the HCa is used as the discharge power of the energy storage battery; At this time, the energy storage battery supplies power to the factory load through the energy storage converter at the discharge power; If the HCa is greater than the maximum discharge power, the energy storage battery is discharged at the maximum discharge power.

9. The energy storage management system of a distributed solar PV system of claim 2, wherein: The specific working process of the monitoring and early warning module is: For each detection period of the factory area on the same day, a plurality of detection points are set, the actual detection generation rate of the photovoltaic power station and the actual detection consumption rate of the factory area are collected, the actual detection generation rate and the actual detection consumption rate are subtracted to obtain the actual production and consumption difference rate; For each detection point, the actual production and consumption difference rate of the detection point and the production and consumption difference rate output by the production and consumption power prediction model at the detection point time are subtracted 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 value, the detection point time is taken as the starting time, the duration that the production and consumption deviation value is greater than the corresponding threshold value is recorded, which is recorded as the early warning duration, and if the early warning duration is greater than the corresponding threshold value, an early warning instruction is generated and sent to the personnel terminal, and the personnel terminal sends workers to manually regulate the charge and discharge strategy in each detection period.

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