Optical storage and charging integrated intelligent management system and method based on virtual power plant platform

Abstract

The invention discloses an optical storage and charging integrated intelligent management system and method based on a virtual power plant platform, relates to the technical field of optical storage and charging, and aims to solve the problems that in energy storage battery management, long-time storage may cause increase of self-discharge rate of batteries and aggravated capacity attenuation, but an existing system often adopts a unified management strategy, batteries with different storage times are not distinguished, and the energy storage efficiency is poor. According to the optical storage and charging integrated intelligent management system and method based on the virtual power plant platform, the storage time and temperature of the energy storage battery are incorporated into a charging and discharging management strategy, so that the service life of the battery is prolonged; the charging and discharging logic can be dynamically adjusted according to charging requirements and light energy input changes, the adaptability of the system to complex conditions is enhanced, energy waste and charging delay are avoided, and the energy utilization efficiency is improved; the maintenance cost and the downtime are reduced, and the overall reliability and flexibility of the system are improved.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic storage and charging technology, and specifically to a photovoltaic storage and charging integrated intelligent management system and method based on a virtual power plant platform. Background Art

[0002] In the integrated photovoltaic storage and charging system, the virtual power plant platform plays a key role. It connects decentralized photovoltaic power generation equipment, energy storage batteries and charging facilities into an organic whole through advanced information technology. On the one hand, the virtual power plant platform can monitor and analyze the power fluctuations of photovoltaic power generation in real time, use the charging and discharging functions of energy storage batteries to adjust the power, smooth the power output, and effectively alleviate the problem of unstable power supply caused by changes in light intensity. On the other hand, in the face of dynamic changes in charging demand, the platform can coordinate the discharge strategy of energy storage batteries, reasonably allocate electricity, ensure the efficiency and stability of the charging process, and improve the friendliness of the entire system to the power grid and the energy utilization efficiency.

[0003] In this regard, the patent document with publication number CN114123158A discloses an integrated photovoltaic storage and charging system, in which a battery group arranged in the integrated photovoltaic storage and charging system is electrically connected to a distribution network by a second circuit breaker, and is connected to a battery management system, and a first circuit breaker is connected between a voltage detection unit and the distribution network. On the premise of realizing the integration of photovoltaic storage and charging, the charging and discharging conditions of the battery can also be selected according to actual usage needs. The system has a wide range of applications and strong adaptability. On the premise of ensuring the reliable operation of the system, the utilization rate of electric energy is improved and the service life of the system is extended.

[0004] In energy storage battery management, as the storage time of the battery increases, the chemical changes inside the battery will cause its performance to change. Long-term storage may increase the battery self-discharge rate and increase capacity attenuation. However, existing systems often adopt a unified management strategy without distinguishing between batteries with different storage times. This accelerates battery aging and reduces the overall service life of the battery.

[0005] In order to solve the above problems, an intelligent management system and method for photovoltaic storage and charging integration based on a virtual power plant platform is proposed. Summary of the invention

[0006] The purpose of the present invention is to provide an integrated intelligent management system and method for photovoltaic storage and charging based on a virtual power plant platform, which solves the problem of insufficient management strategy of photovoltaic storage and charging management system in the background technology.

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: an integrated intelligent management system for photovoltaic storage and charging based on a virtual power plant platform, comprising: an energy storage battery module, a battery status monitoring module, a charging demand detection module, an intelligent decision-making module, a control module and a communication module;

[0008] The energy storage battery module is used to store the electrical energy converted from light energy, and the energy storage battery module is connected to the charging and discharging circuit;

[0009] The battery status monitoring module is installed on the energy storage battery module, measures the battery power based on coulomb counting, obtains the battery temperature through thermistors, and transmits the power and temperature data to the virtual power plant platform. The virtual power plant platform receives the battery power and battery temperature of each energy storage battery module from the battery status monitoring module;

[0010] The charging demand detection module monitors the voltage and current values ​​of the energy storage battery module in real time through the voltage sensor and the current sensor, calculates the real-time power of the solar power generation to determine the power supply status, and transmits the power supply status information to the virtual power plant platform; the voltage and current values ​​detected by the charging demand detection module and the real-time power of the solar power generation are transmitted to the virtual power plant platform;

[0011] The intelligent decision-making module uses the battery power, battery temperature and power supply status received by the virtual power plant platform to formulate charging and discharging strategies;

[0012] In the charging strategy, the charging priority is started, and the energy storage battery module is charged according to the charging priority, and so on, forming a cyclic charging mode;

[0013] In the discharge strategy, the discharge priority is started, and the energy storage battery module is discharged according to the discharge priority;

[0014] The control module controls the on / off of the charging and discharging circuits of the energy storage battery, the size of the charging current, and the size of the discharging current according to the charging strategy and the discharging strategy in the intelligent decision-making module;

[0015] The communication module is used to transmit data information between the battery status monitoring module, charging demand detection module, intelligent decision-making module, and control module and the virtual power plant platform.

[0016] Preferably, the charging priority is as follows:

[0017] The set of energy storage battery modules is B = {b1, b2, ... b n For each energy storage battery module b i ∈B(i=1,2,...,n),p 充1 (b i ) is the first priority charging function, E(b i ) represents the energy storage battery module b i The amount of electricity, E depleted is the circuit exhaustion threshold, Temp(b i ) represents the energy storage battery module b i Temperature, T min ,Tmax | is the normal temperature range of the energy storage battery module;

[0018] First priority, p 充1 (b i )=E(b i )≤E depleted And Temp(b i )∈[T min ,T max ], when p 充1 (b i )=1, the energy storage battery module b i If the first priority is met, charging will be prioritized;

[0019] The second priority, p 充2 (b i )=E(b i )>E depleted And Temp(b i )∈[T min ,T max ] and there exists k∈{1,2,...,6} such that T(b i )=6-(k-1) and

[0020] If T(j) = 6-(k-1), then P 充1 (j) = 0 and P 充2 (j) = 0;

[0021] This formula indicates that when the energy storage battery module is not exhausted and the temperature is normal, and its storage time is in the order of 6 months to 1 month, and other energy storage battery modules are not charged at the first priority during the same storage time, the energy storage battery module b i The second priority charging condition is met;

[0022] Among them, j is the index used to traverse except battery b i The reference to distinguish other energy storage battery modules other than the energy storage battery module, and k is an index used to determine the time condition of the energy storage battery module;

[0023] The third priority, p 充3 (b i ) = just completed discharge and T min ≤Temp(b i )≤T max , when p 充3 (b i )=1, indicating that the energy storage battery module b i Satisfy the third priority charging conditions;

[0024] The discharge priorities are as follows:

[0025] First priority, p 放1 (b i )=Temp(b i )∈[T min ,T max ]and So that T(b i )=3-(k-1) and If T(j) = 3-(k-1), then P 放1 (j) = 0 and P 放2 (j) = 0;

[0026] When the energy storage battery module b i Temperature Temp(b i ) in the normal temperature range [T min ,T max ], and there is a k value that makes the energy storage battery module b i Storage time T(b i ) is equal to 3-(k-1), and for all energy storage battery modules b in the set B that are not equal to i j , if their storage time T(j) is also equal to 3-(k-1), then these energy storage battery modules b j When neither the first priority discharge condition nor the second priority discharge condition is met, p 放1 (b i )=1otherwise p 放1 (b i )=0,

[0027] The second priority, p 放2 (b i )=Temp(b i )∈[T min ,T max ]and Make

[0028] T(b i )=6-(k-1) and If T(j)=6-(k-1), then P 放1 (j) = 0 and P 放2 (j) = 0;

[0029] When the energy storage battery module b i Temperature Temp(b i ) in the normal temperature range [T min ,T max ], and there is a k value that makes the energy storage battery module b i Storage time T(b i ) is equal to T(b i)=6-(k-1), and for all energy storage battery modules b in the set B that are not equal to i j , if their storage time T(j) is also equal to 6-(k-1), then these energy storage battery modules b j When neither the first priority discharge condition nor the second priority discharge condition is met, p 放2 (b i )=1, otherwise p 放2 (b i )=0.

[0030] Preferably, the integrated photovoltaic storage and charging intelligent management system adopts a battery state evaluation algorithm, including a state of charge estimation method and a battery health state evaluation method;

[0031] The state of charge estimation method estimates the battery state of charge of each energy storage battery module by combining the ampere-hour integration method with the open circuit voltage method. The ampere-hour integration method integrates the charge and discharge current of the battery to calculate the change in the battery state of charge. The open circuit voltage method measures the open circuit voltage after the energy storage battery module is stationary based on the relationship between the open circuit voltage of the battery and the battery state of charge to determine the battery state of charge value.

[0032] Preferably, the battery health status evaluation method calculates the battery health status by comparing the current actual available capacity of the energy storage battery module with the initial rated capacity, and combines the internal resistance measurement method to assist in evaluating the battery health status according to the change trend of the internal resistance. The calculation formula is:

[0033] Preferably, the discharge current control algorithm controls the discharge current according to the remaining power, temperature and load demand of the energy storage battery module. When the remaining power of the energy storage battery module is low or the temperature is high, the discharge current is limited by establishing a linear relationship model between the discharge current and the remaining power and temperature of the energy storage battery module.

[0034] Preferably, the control module adopts a charge and discharge control algorithm, including a charging current control algorithm, and adopts a constant current and constant voltage charging algorithm to charge the energy storage battery module with a constant current at the initial charging stage. When the voltage of the energy storage battery module reaches a set upper limit value, it switches to a constant voltage charging mode, and the charging current gradually decreases until the battery is fully charged.

[0035] Preferably, when multiple charging devices are connected at the same time, a proportional allocation algorithm or a priority-based allocation algorithm is used to allocate the discharge power of the energy storage battery module. The proportional allocation algorithm allocates according to the proportion of the required power of each charging device to the total required power, and the priority-based allocation algorithm allocates according to the priority of the charging device or the priority set by the user.

[0036] Preferably, in the constant current and constant voltage charging algorithm, the magnitude of the constant current is set according to the rated capacity of the energy storage battery module, and its value range is 0.1-0.3 times the rated capacity. When the voltage reaches the set upper limit value and switches to the constant voltage mode, the setting accuracy of the constant voltage value is controlled within ±0.5%.

[0037] Preferably, during the operation of the constant current and constant voltage charging algorithm, the system monitors the temperature of the energy storage battery module in real time. When the temperature exceeds the preset safety temperature range of 0°C-45°C, the constant current is automatically adjusted by 5%-10% of the original set value. At the same time, the temperature abnormality information and processing process are recorded to facilitate subsequent analysis and evaluation of the battery health status.

[0038] How to use the integrated intelligent management system for photovoltaic storage and charging based on the virtual power plant platform:

[0039] S1: The battery status monitoring module continuously measures the power and temperature data of each energy storage battery in real time through coulomb counting and thermistor, stores the power and temperature data in the local database according to the set data format and storage rules, and updates the relevant status information of the battery at the same time;

[0040] The charging demand detection module uses voltage sensors and current sensors to monitor the voltage and current values ​​output by the photovoltaic power generation system in real time, calculates the real-time power of photovoltaic power generation, and determines the power supply status. The power supply status information is then transmitted to the virtual power plant platform, which receives and stores this information to provide data support for the intelligent decision-making module.

[0041] S2: The intelligent decision-making module formulates charging and discharging strategies and calculates charging and discharging priorities based on the battery status monitoring data, charging demand information, solar power generation status, and system operation history data obtained from the virtual power plant platform, and gives priority to charging and discharging batteries with high charging priorities;

[0042] S3: The control module accurately controls the on / off, charging current, and discharging current of the energy storage battery’s charging and discharging circuits according to the charging and discharging strategies developed by the intelligent decision-making module; the communication module ensures smooth data interaction and command transmission between modules within the system.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] 1. The integrated intelligent management system and method for photovoltaic storage and charging based on a virtual power plant platform provided by the present invention improves the battery life by incorporating the storage time and temperature of the energy storage battery into the charging and discharging management strategy, and can dynamically adjust the charging and discharging logic according to the charging demand and changes in the light energy input, thereby enhancing the system's adaptability to complex situations, avoiding energy waste and charging delays, and improving energy utilization efficiency; reducing maintenance costs and downtime, and improving the overall reliability and flexibility of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is a system flow chart of the present invention;

[0046] Figure 2 It is a circuit connection schematic diagram of the present invention;

[0047] Figure 3 It is a schematic diagram of the discharge process of the present invention;

[0048] Figure 4 It is a schematic diagram of the charging process structure of the present invention. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0050] In order to further understand the content of the present invention, the present invention is described in detail in conjunction with the accompanying drawings.

[0051] Combination Figure 1-Figure 4 The photovoltaic storage and charging integrated intelligent management system based on the virtual power plant platform of the present invention includes:

[0052] Energy storage battery module, battery status monitoring module, charging demand detection module, intelligent decision-making module, control module and communication module;

[0053] The energy storage battery module is used to store the electrical energy converted from light energy, and the energy storage battery module is connected to the charging and discharging circuit;

[0054] The battery status monitoring module is installed on the energy storage battery module, measures the battery power based on coulomb counting, obtains the battery temperature through thermistors, and transmits the power and temperature data to the virtual power plant platform. The virtual power plant platform receives the battery power and battery temperature of each energy storage battery module from the battery status monitoring module, and converges them to the virtual power plant platform through the data transmission protocol. By accurately tracking the amount of charge flowing through the energy storage battery module during the charging and discharging process, the current power of the energy storage battery module can be accurately calculated. At the same time, the module is equipped with highly sensitive thermistors, which are in close contact with the energy storage battery module and can keenly sense the subtle changes in the temperature of the energy storage battery module, thereby obtaining real-time temperature data. After obtaining the power and temperature data, the energy storage battery module status monitoring module will quickly and accurately transmit these key data to the virtual power plant platform through a stable and efficient communication link, providing a solid data foundation for the intelligent decision-making of the entire system and ensuring the system's accurate control and reasonable management of the energy storage battery status.

[0055] In this integrated intelligent management system for photovoltaic storage and charging, an advanced and accurate battery status assessment algorithm is adopted. This algorithm is the key to ensure the efficient operation of the system and the rational use of batteries. The system adopts a battery status assessment algorithm, including a charge status estimation method and a battery health status assessment method;

[0056] The state of charge estimation method estimates the battery state of charge of each energy storage battery by combining the ampere-hour integration method with the open circuit voltage method, wherein the ampere-hour integration method integrates the charge and discharge current of the battery to calculate the change of the battery state of charge;

[0057] Specifically, through the formula: Where S0C(t) represents the charge state at time t, S0C(t0) is the charge state at the initial time t0, and C n is the rated capacity of the battery, I(γ) is the charge and discharge current that changes with time γ; the ampere-hour integration method has a certain error accumulation problem, and the open circuit voltage method plays an important calibration role at this time. The open circuit voltage method is based on the inherent internal relationship between the open circuit voltage of the battery and the battery state of charge. When the battery is left to stand for a long enough time, its open circuit voltage V is measured. oc , and then use the pre-built SOC-V oc Relationship curve, accurately determine the battery state of charge value.

[0058] The open circuit voltage method is based on the relationship between the open circuit voltage of the battery and the battery state of charge. The open circuit voltage is measured after the battery is at rest to determine the battery state of charge value. The battery health status evaluation method calculates the battery health status by comparing the current actual available capacity of the battery with the initial rated capacity, and combines the internal resistance measurement method to assist in evaluating the battery health status according to the change trend of the internal resistance. The calculation formula is:

[0059] The charging demand detection module monitors the voltage and current values ​​of the energy storage battery module in real time through the voltage sensor and the current sensor, calculates the real-time power of the solar power generation to determine the power supply status, and transmits the power supply status information to the virtual power plant platform; the voltage and current values ​​detected by the charging demand detection module and the real-time power of the solar power generation are transmitted to the virtual power plant platform;

[0060] The intelligent decision-making module uses the battery power, battery temperature and power supply status received by the virtual power plant platform to formulate charging and discharging strategies;

[0061] The intelligent decision-making module is divided into charging strategy and discharging strategy;

[0062] In the charging strategy, the charging priority is started, and the energy storage battery module is charged according to the charging priority, and so on, forming a cyclic charging mode;

[0063] In the discharge strategy, the discharge priority is started, and the energy storage battery module is discharged according to the discharge priority;

[0064] The control module controls the on / off of the charging and discharging circuits of the energy storage battery, the size of the charging current, and the size of the discharging current according to the charging strategy and the discharging strategy in the intelligent decision-making module;

[0065] The charging priorities are as follows:

[0066] The set of energy storage battery modules is B = {b1, b2, ... b n For each energy storage battery module b i ∈B(i=1,2,...,n),p 充1 (b i ) is the first priority charging function, E(b i ) represents the energy storage battery module b i The amount of electricity, E depleted is the circuit exhaustion threshold, Temp(b i ) represents the energy storage battery module b i The temperature, |T min ,T max | is the normal temperature range of the energy storage battery module;

[0067] First priority, p 充1 (b i )=E(b i )≤E depleted And Temp(b i )∈[T min ,T max ], when p 充1 (b i )=1, the energy storage battery module bi If the first priority is met, charging will be prioritized;

[0068] The second priority, p 充2 (b i )=E(b i )>E depleted And Temp(b i )∈[T min ,T max ] and there exists k∈{1,2,...,6} such that T(b i )=6-(k-1) and

[0069] If T(j) = 6-(k-1), then P 充1 (j) = 0 and P 充2 (j) = 0;

[0070] This formula indicates that when the energy storage battery module is not exhausted and the temperature is normal, and its storage time is in the order of 6 months to 1 month, and other energy storage battery modules are not charged at the first priority during the same storage time, the energy storage battery module b i The second priority charging condition is met;

[0071] Among them, j is the index used to traverse except battery b i The reference to distinguish other energy storage battery modules other than the energy storage battery module, and k is an index used to determine the time condition of the energy storage battery module;

[0072] The third priority, p 充3 (b i ) = just completed discharge and T min ≤Temp(b i )≤T max , when p 充3 (b i )=1, indicating that the energy storage battery module b i Satisfy the third priority charging conditions;

[0073] The discharge priorities are as follows:

[0074] First priority, p 放1 (b i )=Temp(b i )∈[T min ,T max ]and So that T(b i )=3-(k-1) and If T(j) = 3-(k-1), then P 放1 (j) = 0 and P 放2 (j) = 0;

[0075] When the energy storage battery module b i Temperature Temp(b i ) in the normal temperature range [T min ,T max ], and there is a k value that makes the energy storage battery module b i Storage time T(b i ) is equal to 3-(k-1), and for all energy storage battery modules b in the set B that are not equal to i j , if their storage time T(j) is also equal to 3-(k-1), then these energy storage battery modules b j When neither the first priority discharge condition nor the second priority discharge condition is met, p 放1 (b i )=1otherwise p 放1 (b i )=0,

[0076] The second priority, p 放2 (b i )=Temp(b i )∈[T min ,T max ]and Make

[0077] T(b i )=6-(k-1) and If T(j)=6-(k-1), then P 放1 (j) = 0 and P 放2 (j) = 0;

[0078] When the energy storage battery module b i Temperature Temp(b i ) in the normal temperature range [T min ,T max ], and there is a k value that makes the energy storage battery module b i Storage time T(b i ) is equal to T(b i )=6-(k-1), and for all energy storage battery modules b in the set B that are not equal to i j , if their storage time T(j) is also equal to 6-(k-1), then these energy storage battery modules b j When neither the first priority discharge condition nor the second priority discharge condition is met, p 放2 (b i )=1, otherwise p 放2 (b i )=0.

[0079] In the charging priority, the empty capacity energy storage batteries with exhausted power and normal temperature are selected first. Since these batteries have no power reserves, they will not be able to provide energy storage support for the system if they are not charged first, which will seriously affect the normal operation and emergency power supply capacity of the solar storage and charging system, so they are charged first.

[0080] Secondly, according to the storage time, priority should be given to charging batteries that have been stored for a long time and at normal temperature. The order is 6 months, 5 months, 4 months, 3 months, 2 months, and 1 month. The self-discharge of batteries stored for a long time causes a large loss of power. Timely charging can reduce the battery performance degradation and life loss caused by staying in a low-power state for too long, and maintain the battery in a good performance state.

[0081] Finally, for the energy storage battery that has completed discharge and has normal temperature, timely charging of the discharged battery can reduce the time in the low-power state, reduce the impact of self-discharge, keep the battery healthy, help extend its service life, and improve its availability during the next discharge.

[0082] By giving priority to charging depleted batteries, the basic energy storage and power supply continuity of the system is guaranteed, avoiding system failure or power outage due to lack of power in key batteries. The charging sequence is arranged according to the storage time, which can effectively manage the long-term energy storage state of the battery, so that the power and performance of each battery are maintained at a relatively balanced level, extending the overall life of the entire energy storage battery pack, reducing the need for early replacement of individual batteries due to excessive aging, and reducing operating costs. The timely charging of batteries that have just been discharged improves the battery's charge and discharge cycle efficiency, allowing the battery to play a more stable role in the system, enhancing the reliability and stability of the system, and also helping to better cope with different power demands and scenario changes.

[0083] In the priority allocation of charging, for energy storage batteries with a storage time of 3 months, 2 months, and 1 month and a normal temperature, the batteries with a shorter storage time are given priority for discharge. This can avoid the accelerated aging of batteries stored for a long time due to excessive discharge and ensure that the system has a relatively stable power output during the discharge process, because batteries with a shorter storage time usually have relatively better performance and power retention;

[0084] In addition, for energy storage batteries with a storage time of 4 months, 5 months, and 6 months and normal temperature, when the first priority battery cannot meet the discharge demand, the battery with a longer storage time will be selected to ensure the power supply of the system while minimizing the adverse effects on the battery life. The energy supply of the system and the maintenance of battery life can be balanced through a reasonable sequence arrangement. Prioritizing the use of batteries with a short storage time for discharge protects the newer or recently used batteries in the battery pack to the greatest extent, reduces the discharge pressure of batteries that have been idle for a long time, and reduces the speed of their performance degradation, thereby extending the service life of the entire battery pack and improving the utilization rate of battery assets. Reasonable arrangement of batteries with a long storage time as subsequent discharge options ensures that the system has sufficient power supply in various power demand scenarios, enhances the power supply reliability and adaptability of the system, and can operate relatively stably whether it is dealing with peak power consumption or long-term off-grid power supply, reducing the risk of power outages due to insufficient power, and improving user experience and the overall value of the system.

[0085] In addition, in the entire charge and discharge priority allocation, only batteries with normal temperatures will be included in the priority allocation again. Batteries with normal temperatures have relatively stable internal chemical reactions and can provide relatively stable and reliable voltage and current outputs. During the discharge process, if a battery with abnormal temperature is included, the unstable internal reaction of the battery may cause voltage fluctuations, current mutations, etc., affecting the normal operation of electrical equipment and may even damage some sensitive equipment.

[0086] The charging priority calculation in the intelligent decision-making module is dynamically weighted. The system sets up an intelligent evaluation mechanism based on the continuous running time of the system. As the system continues to run, the system monitors the changes in performance and health status of batteries with longer storage cycles over time. Based on these changes, the system increases the weight of the battery storage cycle in the charging priority evaluation.

[0087] The method for the intelligent decision-making module to adjust the strategy during the charging and discharging process is as follows:

[0088] During the charging process, if the battery voltage V is higher than the charging cut-off voltage V max Or lower than the charging start voltage V min , or the battery temperature T b Higher than the charging high temperature threshold T 充电-max Or below the charging low temperature threshold T 充电-min , then suspend charging of the battery, recalculate the charging priority, and adjust the charging strategy;

[0089] During the discharge process, if the battery voltage V is lower than the discharge cut-off voltage V 放电-min or battery temperature T b Higher than the discharge high temperature threshold T放电-max , the battery discharge is suspended, the discharge priority is recalculated, and the discharge strategy is adjusted. The charge cut-off voltage, charge start voltage, charge high temperature threshold, charge low temperature threshold, discharge cut-off voltage, and discharge high temperature threshold are determined according to the battery type and system requirements.

[0090] The control module controls the charge and discharge circuit of the energy storage battery according to the instructions of the intelligent decision-making module, accurately controls the on and off, charging current and discharge current of the charge and discharge circuit of the energy storage battery, and the discharge current control algorithm controls the discharge current according to the remaining power, temperature and load demand of the battery. When the remaining power of the battery is low or the temperature is high, the discharge current is limited by establishing a linear relationship model between the discharge current and the remaining power and temperature of the battery;

[0091] The magnitude of the discharge current is determined by a linear relationship model. The discharge current is linearly related to the remaining battery power and temperature. The discharge current is I d , the remaining battery power is Q r , when the battery temperature is T, the relationship between them can be expressed as I d =k1×Q r +k2×T+b. Among them, k1 is a coefficient related to the remaining battery power, which determines the degree of influence of the remaining power on the discharge current. The value of k1 is positive, and the more the remaining battery power is, the greater the positive contribution to the discharge current, that is, the greater the allowable discharge current. For example, if the value of k1 is large, then when the remaining power increases, the discharge current will have a more obvious increasing trend.

[0092] k2 is a coefficient related to battery temperature. Since the discharge current needs to be limited when the temperature is high, the value of k2 is negative. This means that as the battery temperature rises, the discharge current will decrease accordingly. For example, when the temperature rises, k2 will cause the discharge current to decrease proportionally, thereby preventing the battery from being damaged due to excessive discharge at high temperatures.

[0093] b is a constant term that provides a basic reference value for the entire discharge current control.

[0094] The control module adopts a charge and discharge control algorithm, including a charging current control algorithm, and a constant current-constant voltage charging algorithm. In the initial stage of charging, the energy storage battery is charged with a constant current. When the battery voltage reaches the set upper limit, it switches to a constant voltage charging mode, and the charging current gradually decreases until the battery is fully charged. In the constant current and constant voltage charging algorithm, the size of the constant current is set according to the rated capacity of the energy storage battery module, and its value range is 0.1-0.3 times the rated capacity. When the voltage reaches the set upper limit and switches to the constant voltage mode, the setting accuracy of the constant voltage value is controlled within ±0.5%;

[0095] During the operation of the constant current and constant voltage charging algorithm, the system monitors the temperature of the energy storage battery module in real time. When the temperature exceeds the preset safety temperature range of 0℃-45℃, the constant current is automatically adjusted by 5%-10% of the original set value. At the same time, the temperature abnormality information and processing process are recorded to facilitate subsequent analysis and evaluation of the battery health status.

[0096] The communication module is used to transmit data information between the battery status monitoring module, charging demand detection module, intelligent decision-making module, and control module and the virtual power plant platform.

[0097] How to use the integrated intelligent management system for photovoltaic storage and charging based on the virtual power plant platform:

[0098] S1: The battery status monitoring module continuously measures the power and temperature data of each energy storage battery in real time through coulomb counting and thermistor, stores the power and temperature data in the local database according to the set data format and storage rules, and updates the relevant status information of the battery at the same time;

[0099] The charging demand detection module uses voltage sensors and current sensors to monitor the voltage and current values ​​output by the photovoltaic power generation system in real time, calculates the real-time power of photovoltaic power generation, and determines the power supply status. The power supply status information is then transmitted to the virtual power plant platform, which receives and stores this information to provide data support for the intelligent decision-making module.

[0100] S2: The intelligent decision-making module formulates charging and discharging strategies and calculates charging and discharging priorities based on the battery status monitoring data, charging demand information, solar power generation status, and system operation history data obtained from the virtual power plant platform, and gives priority to charging and discharging batteries with high charging priorities;

[0101] S3: The control module accurately controls the on / off, charging current, and discharging current of the energy storage battery’s charging and discharging circuits according to the charging and discharging strategies developed by the intelligent decision-making module; the communication module ensures smooth data interaction and command transmission between modules within the system.

[0102] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0103] Although 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 the embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An integrated intelligent management system for photovoltaic storage and charging based on a virtual power plant platform, characterized by: include: Energy storage battery module, battery status monitoring module, charging demand detection module, intelligent decision-making module, control module and communication module; The energy storage battery module is used to store the electrical energy converted from light energy, and the energy storage battery module is connected to the charging and discharging circuit; The battery status monitoring module is installed on the energy storage battery module, measures the battery power based on coulomb counting, obtains the battery temperature through thermistors, and transmits the power and temperature data to the virtual power plant platform. The virtual power plant platform receives the battery power and battery temperature of each energy storage battery module from the battery status monitoring module; The charging demand detection module monitors the voltage and current values ​​of the energy storage battery module in real time through the voltage sensor and the current sensor, calculates the real-time power of the solar power generation to determine the power supply status, and transmits the power supply status information to the virtual power plant platform; The voltage and current values ​​detected by the charging demand detection module and the real-time power of solar power generation are transmitted to the virtual power plant platform; The intelligent decision-making module uses the battery power, battery temperature and power supply status received by the virtual power plant platform to formulate charging and discharging strategies; In the charging strategy, the charging priority is started, and the energy storage battery module is charged according to the charging priority, and so on, forming a cyclic charging mode; In the discharge strategy, the discharge priority is started, and the energy storage battery module is discharged according to the discharge priority; The control module controls the on / off of the charging and discharging circuits of the energy storage battery, the size of the charging current, and the size of the discharging current according to the charging strategy and the discharging strategy in the intelligent decision-making module; The communication module is used to transmit data information between the battery status monitoring module, charging demand detection module, intelligent decision-making module, and control module and the virtual power plant platform.

2. The photovoltaic storage and charging integrated intelligent management system based on the virtual power plant platform according to claim 1 is characterized by: The charging priorities are as follows: The set of energy storage battery modules is B = {b1, b2, ... b n For each energy storage battery module b i ∈B(i=1,2,...,n),p 充1 (b i ) is the first priority charging function, E(b i ) represents the energy storage battery module b i The amount of electricity, E depleted is the circuit exhaustion threshold, Temp(b i ) represents the energy storage battery module b i Temperature, T min ,T max | is the normal temperature range of the energy storage battery module; First priority, p 充1 (b i )=E(b i )≤E depleted And Temp(b i )∈[T min ,T max ], when p 充1 (b i )=1, the energy storage battery module b i If the first priority is met, charging will be prioritized; The second priority, p 充2 (b i )=E(b i )>E depleted And Temp(b i )∈[T min ,T max ] and there exists k∈{1,2,...,6} such that T(b i )=6-(k-1) and If T(j) = 6-(k-1), then P 充1 (j) = 0 and P 充2 (j) = 0; This formula indicates that when the energy storage battery module is not exhausted and the temperature is normal, and its storage time is in the order of 6 months to 1 month, and other energy storage battery modules are not charged at the first priority during the same storage time, the energy storage battery module b i The second priority charging condition is met; Among them, j is the index used to traverse except battery b i The reference to distinguish other energy storage battery modules other than the energy storage battery module, and k is an index used to determine the time condition of the energy storage battery module; The third priority, p 充3 (b i ) = just completed discharge and T min ≤Temp(b i )≤T max , when p 充3 (b i )=1, indicating that the energy storage battery module b i Satisfy the third priority charging conditions; The discharge priorities are as follows: First priority, p 放1 (b i )=Temp(b i )∈[T min ,T max ]and So that T(b i )=3-(k-1) and If T(j) = 3-(k-1), then P 放1 (j) = 0 and P 放2 (j) = 0; When the energy storage battery module b i Temperature Temp(b i ) in the normal temperature range [T min ,T max ], and there is a k value that makes the energy storage battery module b i Storage time T(b i ) is equal to 3-(k-1), and for all energy storage battery modules b in the set B that are not equal to i j , if their storage time T(j) is also equal to 3-(k-1), then these energy storage battery modules b j When neither the first priority discharge condition nor the second priority discharge condition is met, p 放1 (b i )=1otherwise p 放1 (b i )=0, The second priority, p 放2 (b i )=Temp(b i )∈[T min ,T max ]and Make T(b i )=6-(k-1) and If T(j)=6-(k-1), then P 放1 (j) = 0 and P 放2 (j) = 0; When the energy storage battery module b i Temperature Temp(b i ) in the normal temperature range [T min ,T max ], and there is a k value that makes the energy storage battery module b i Storage time T(b i ) is equal to T(b i )=6-(k-1), and for all energy storage battery modules b in the set B that are not equal to i j , if their storage time T(j) is also equal to 6-(k-1), then these energy storage battery modules b j When neither the first priority discharge condition nor the second priority discharge condition is met, p 放2 (b i )=1, otherwise p 放2 (b i )=0.

3. The photovoltaic storage and charging integrated intelligent management system based on the virtual power plant platform according to claim 1 is characterized by: The integrated photovoltaic storage and charging intelligent management system adopts a battery status assessment algorithm, including a state of charge estimation method and a battery health status assessment method; The state of charge estimation method estimates the battery state of charge of each energy storage battery module by combining the ampere-hour integration method with the open circuit voltage method. The ampere-hour integration method integrates the charge and discharge current of the battery to calculate the change in the battery state of charge. The open circuit voltage method measures the open circuit voltage after the energy storage battery module is stationary based on the relationship between the open circuit voltage of the battery and the battery state of charge to determine the battery state of charge value.

4. The photovoltaic storage and charging integrated intelligent management system based on the virtual power plant platform according to claim 3 is characterized by: The battery health status assessment method calculates the battery health status by comparing the current actual available capacity of the energy storage battery module with the initial rated capacity, and combines the internal resistance measurement method to assist in assessing the battery health status based on the change trend of the internal resistance. The calculation formula is:

5. The photovoltaic storage and charging integrated intelligent management system based on the virtual power plant platform according to claim 1 is characterized by: The discharge current control algorithm controls the discharge current according to the remaining power, temperature and load demand of the energy storage battery module. When the remaining power of the energy storage battery module is low or the temperature is high, the discharge current is limited by establishing a linear relationship model between the discharge current and the remaining power and temperature of the energy storage battery module.

6. The photovoltaic storage and charging integrated intelligent management system based on the virtual power plant platform according to claim 1 is characterized by: The control module adopts a charge and discharge control algorithm, including a charging current control algorithm, and a constant current and constant voltage charging algorithm. In the initial charging stage, the energy storage battery module is charged with a constant current. When the voltage of the energy storage battery module reaches the set upper limit, it switches to a constant voltage charging mode, and the charging current gradually decreases until the battery is fully charged.

7. The photovoltaic storage and charging integrated intelligent management system based on the virtual power plant platform according to claim 1 is characterized by: When multiple charging devices are connected at the same time, a proportional allocation algorithm or a priority-based allocation algorithm is used to allocate the discharge power of the energy storage battery module. The proportional allocation algorithm allocates according to the proportion of the required power of each charging device to the total required power, and the priority-based allocation algorithm allocates according to the priority of the charging device or the priority set by the user.

8. The photovoltaic storage and charging integrated intelligent management system based on the virtual power plant platform according to claim 6 is characterized by: In the constant current and constant voltage charging algorithm, the size of the constant current is set according to the rated capacity of the energy storage battery module, and its value range is 0.1-0.3 times the rated capacity. When the voltage reaches the set upper limit value and switches to the constant voltage mode, the setting accuracy of the constant voltage value is controlled within ±0.5%.

9. The photovoltaic storage and charging integrated intelligent management system based on the virtual power plant platform according to claim 8 is characterized by: During the operation of the constant current and constant voltage charging algorithm, the system monitors the temperature of the energy storage battery module in real time. When the temperature exceeds the preset safety temperature range of 0℃-45℃, the constant current is automatically adjusted by 5%-10% of the original set value. At the same time, the temperature abnormality information and processing process are recorded to facilitate subsequent analysis and evaluation of the battery health status.

10. The method for using the photovoltaic storage and charging integrated intelligent management system based on the virtual power plant platform according to any one of claims 1 to 9, characterized in that: S1: The battery status monitoring module continuously measures the power and temperature data of each energy storage battery in real time through coulomb counting and thermistor, stores the power and temperature data in the local database according to the set data format and storage rules, and updates the relevant status information of the battery at the same time; The charging demand detection module uses voltage sensors and current sensors to monitor the voltage and current values ​​output by the photovoltaic power generation system in real time, calculates the real-time power of photovoltaic power generation, and determines the power supply status. The power supply status information is then transmitted to the virtual power plant platform, which receives and stores this information to provide data support for the intelligent decision-making module. S2: The intelligent decision-making module formulates charging and discharging strategies and calculates charging and discharging priorities based on the battery status monitoring data, charging demand information, solar power generation status, and system operation history data obtained from the virtual power plant platform, and gives priority to charging and discharging batteries with high charging priorities; S3: The control module accurately controls the on / off, charging current, and discharging current of the energy storage battery’s charging and discharging circuits according to the charging and discharging strategies developed by the intelligent decision-making module; the communication module ensures smooth data interaction and command transmission between modules within the system.

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