Integrated photovoltaic energy storage management system and control method thereof

Abstract

The invention provides an integrated photovoltaic energy storage management system and a control method thereof.The integrated photovoltaic energy storage management system comprises a photovoltaic power generation module, an energy storage module, an energy management module, a power grid interaction module, a load management module, a communication and control system and a user interface, and relates to the technical field of new energy. The state information of photovoltaic power generation, energy storage and load is monitored and analyzed in real time, the energy distribution and scheduling strategy is optimized, photovoltaic power generation is preferentially used, redundant electric energy is reasonably stored and utilized, the energy utilization efficiency is effectively improved, and compared with a traditional photovoltaic energy storage system, solar energy resources can be more fully utilized, and the energy utilization efficiency is improved. The loss of energy in the conversion and transmission process is reduced, and the degree of dependence on a power grid is reduced, so that the power utilization cost is reduced.

Description

Technical Field

[0001] The present invention relates to the field of new energy technologies, and particularly to an integrated photovoltaic energy storage management system and its control method, which are applicable to scenarios such as households, industrial and commercial enterprises, and microgrids, and can achieve intelligent integration of photovoltaic power generation, energy storage, and energy management. Background Art

[0002] With the increasing global demand for clean energy, the proportion of renewable energy in the energy structure has been continuously rising. Among them, photovoltaic power generation has become one of the important ways to obtain clean energy due to its rich resources and pollution-free advantages. However, the characteristics of photovoltaic power generation itself determine that it has intermittency and instability. For example, when the light conditions are poor, such as on cloudy days or at night, the photovoltaic power generation will drop significantly or even stop; while when the light is strong, the power generation may exceed the local load demand. This power generation characteristic makes it difficult to fully match the grid load demand, posing challenges to the stability and reliability of power supply.

[0003] To alleviate this problem, energy storage technology has been introduced into the photovoltaic system. However, there are many drawbacks in the current photovoltaic energy storage systems on the market. First of all, the collaborative control efficiency between photovoltaic power generation, energy storage devices, and loads is low. During the actual operation process, there is a lack of effective information interaction and collaborative mechanism among various parts, resulting in a large amount of energy loss during the conversion and transmission process, and the energy utilization rate is not high. For example, when the photovoltaic power generation is sufficient, the excess electric energy cannot be stored in the energy storage device in a timely and reasonable manner, or when the load demand changes, the discharge strategy of the energy storage device cannot be quickly adjusted to meet the demand.

[0004] Secondly, the system has insufficient intelligence. The existing photovoltaic energy storage systems often have difficulty in performing dynamic energy management and optimal scheduling according to multiple factors such as real-time light intensity, battery state, load changes, and grid conditions. Most systems can only operate according to preset simple rules and cannot flexibly cope with complex and changeable actual working conditions, resulting in the inability to further improve the energy utilization efficiency.

[0005] In addition, many current photovoltaic energy storage systems lack the ability to respond to the grid state in real time. When the grid fluctuates, fails, or requires auxiliary services (such as peak shaving, frequency modulation, etc.), these systems cannot participate in it in a timely and effective manner and cannot fully play their role in stabilizing the grid operation.

[0006] In summary, the existing photovoltaic energy storage systems have obvious deficiencies in collaborative control, intelligence level, and grid response ability. There is an urgent need for an efficient and intelligent integrated photovoltaic energy storage management system to solve the above problems and improve the overall performance and reliability of the photovoltaic energy storage system. Summary of the Invention

[0007] To overcome the existing problems, the embodiments of the present application provide an integrated photovoltaic energy storage management system and its control method. Through an intelligent energy management system, the status information of photovoltaic power generation, energy storage, and loads is monitored and analyzed in real time, the energy distribution and scheduling strategies are optimized, photovoltaic power generation is preferentially used, and the excess electric energy is reasonably stored and utilized, effectively improving the energy utilization efficiency. Compared with traditional photovoltaic energy storage systems, it can make more full use of solar energy resources, reduce the losses during energy conversion and transmission, reduce the dependence on the power grid, and thus reduce the electricity cost.

[0008] The technical solutions adopted by the embodiments of the present application to solve its technical problems are as follows:

[0009] An integrated photovoltaic energy storage management system and its control method, including a photovoltaic power generation module, an energy storage module, an energy management module, a grid interaction module, a load management module, a communication and control system, and a user interface; wherein,

[0010] The photovoltaic power generation module includes photovoltaic components and an inverter, and is used to convert solar energy into electric energy;

[0011] Among them, the photovoltaic components are the core components for realizing photovoltaic conversion. Based on the photovoltaic effect, they convert solar photons into electrons, thereby generating direct current. Different types of photovoltaic components (such as monocrystalline silicon, polycrystalline silicon, thin-film photovoltaic components, etc.) have different photovoltaic conversion efficiencies and characteristics, and can be selected according to the actual application scenarios and requirements. The inverter is responsible for converting the direct current generated by the photovoltaic components into alternating current that meets the requirements of the power grid or loads. Its conversion efficiency and output power quality directly affect the overall performance of the photovoltaic power generation module. For example, by adopting advanced sine pulse width modulation (SPWM) technology or space vector pulse width modulation (SVPWM) technology, the quality of the alternating current output by the inverter can be effectively improved, and the harmonic content can be reduced;

[0012] The energy storage module includes a battery pack and a battery management system (BMS), and is used to store and release electric energy;

[0013] Among them, the battery pack is the carrier for electric energy storage. Different types of batteries (such as lead-acid batteries, lithium-ion batteries, sodium-sulfur batteries, etc.) have different energy densities, charge and discharge efficiencies, cycle lives, and costs, etc. characteristics, and need to be selected according to the specific application scenarios and budgets of the system. The BMS is the key control unit of the energy storage module. It monitors various parameters of the battery pack in real time, such as voltage, current, temperature, state of charge (SOC), etc. Through the precise monitoring and analysis of these parameters, the BMS realizes functions such as charge and discharge control, balance management, and fault diagnosis of the battery pack, ensuring the safe and efficient operation of the battery pack and extending the battery life. For example, when the voltage of a single battery in the battery pack is too high or too low, the BMS can adjust it through the balancing circuit to make each single battery maintain a consistent charging state;

[0014] The energy management module includes an Energy Management System (EMS) for optimizing energy distribution and scheduling;

[0015] Among them, the EMS comprehensively analyzes the data information from the photovoltaic power generation module, energy storage module, load management module, and grid interaction module, and uses advanced optimization algorithms (such as linear programming, dynamic programming, etc.) to make energy optimization distribution and scheduling decisions. For example, according to factors such as real-time light intensity, battery SOC value, load power demand, and grid electricity price, the EMS formulates optimal power generation, energy storage, and power consumption strategies to ensure the efficient use of energy and cost minimization. At the same time, the EMS also has the function of data interaction and instruction transmission with other system modules to achieve the coordinated operation of the entire system;

[0016] The grid interaction module includes a grid-connected inverter and a protection device for realizing bidirectional power exchange with the grid;

[0017] Among them, the grid-connected inverter is responsible for realizing bidirectional power exchange with the grid, delivering the excess electric energy generated by the photovoltaic power generation module to the grid, and obtaining electric energy from the grid when needed. To ensure the stability of the grid connection process and power quality, the grid-connected inverter needs to meet strict grid access standards, such as requirements for frequency, voltage deviation, harmonic content, etc. The protection device monitors the operating status of the grid and the system in real time. When abnormal conditions such as overvoltage, undervoltage, overcurrent, and leakage occur, it quickly cuts off the circuit to protect the safety of system equipment and personnel. For example, when the grid voltage exceeds the normal range, the protection device immediately acts to prevent high voltage from damaging the electrical equipment in the system;

[0018] The load management module includes an intelligent load controller for adjusting the load according to the energy supply situation;

[0019] Among them, the controller intelligently adjusts the connected load according to the energy supply situation, such as photovoltaic power generation, energy storage battery power, and grid electricity price. For some adjustable loads (such as smart home appliances, industrial equipment, etc.), the intelligent load controller can interact with the load through a communication interface (such as ZigBee, Wi-Fi, Bluetooth, etc.), and adjust the operating power or operating time of the load according to the set strategy. For example, when the photovoltaic power generation is sufficient and the grid electricity price is high, the intelligent load controller can give priority to starting high-power loads to make full use of low-cost photovoltaic power generation; when the photovoltaic power generation is insufficient or the grid electricity price is low, it appropriately reduces the power of non-critical loads or delays their operating time to achieve reasonable use of energy and cost control;

[0020] The communication and control system includes a communication module and a control system for realizing data transmission and instruction execution between modules;

[0021] Among them, the communication module is responsible for realizing data transmission between system modules, ensuring accurate and real-time interaction of information. Multiple communication methods can be adopted. For example, wired communication (such as RS485, Ethernet, etc.) is applicable to modules with relatively short distances, large data transmission volumes, and high stability requirements; wireless communication (such as ZigBee, LoRa, 4G / 5G, etc.) is applicable to scenarios with relatively long distances, difficult wiring, or the need for mobility. The control system receives data information from each module and coordinates the control of each module according to the preset control strategy and the instructions of the EMS to ensure the stable operation of the system. For example, when the EMS issues an instruction to adjust the output power of the photovoltaic power generation module, the control system conveys the instruction to the inverter of the photovoltaic power generation module through the communication module to achieve precise adjustment of the power generation power;

[0022] The user interface includes a mobile application and a Web interface, which are used to monitor the system status and energy consumption data in real time;

[0023] Among them, the mobile application facilitates users to monitor the system status and energy consumption data at any time and place through mobile devices such as mobile phones and tablets, and has the characteristics of convenient operation and strong real-time performance. The Web interface provides a more comprehensive and detailed display and management function of system information. Users can access it through a computer browser and it is applicable to scenarios that require in-depth data analysis and system configuration. The user interface not only displays the operating parameters of the system in real time, such as photovoltaic power generation, energy storage battery power, load power, grid interaction power, etc., but also provides a statistical analysis function of energy consumption data to help users understand the energy usage situation and formulate energy-saving strategies. At the same time, users can remotely control some devices (such as intelligent loads, charging devices, etc.) through the user interface to achieve a more intelligent energy management experience.

[0024] Preferably, the energy management module realizes energy optimization scheduling through an energy management system (EMS), and its optimization objective function is:

[0025] min(C grid *P grid +C battery *P battery )

[0026] Among them, C grid is the grid electricity price, P grid is the power obtained from the grid, C battery is the battery charge and discharge cost, and P battery is the battery charge and discharge power.

[0027] Preferably, the energy management system (EMS) needs to meet the following constraint conditions during the scheduling process:

[0028] P pv +P battery +Pgrid = P load

[0029] Wherein, P pv is the photovoltaic power generation power, and P load is the load demand power.

[0030] Preferably, the battery charge and discharge state (SOC) of the energy storage module is calculated by the following formula:

[0031]

[0032] Wherein, SOC(t) is the battery state at the current moment, SOC(t - 1) is the battery state at the previous moment, Δt is the time interval, and E max is the maximum capacity of the battery.

[0033] Preferably, the output power P inv of the grid-connected inverter of the grid interaction module satisfies the following relationship:

[0034] P inv = η * P DC

[0035] Wherein, η is the inverter efficiency, and P DC is the DC input power.

[0036] Preferably, the load priority control strategy of the load management module is implemented by the following formula:

[0037] P critical ≤ P pv + P battery + P grid

[0038] Wherein, P critical is the power demand of the critical load.

[0039] Preferably, the user interface displays the energy balance state in real time, and its energy balance formula is:

[0040] E pv + E battery + E grid = E load

[0041] Wherein, E pv is the photovoltaic power generation energy, E battery is the battery charge and discharge energy, E grid is the grid interaction energy, and E load is the load consumption energy.

[0042] Including the following steps:

[0043] Step 1: Collect photovoltaic power generation data, energy storage status, load demand, and grid information in real time;

[0044] Step 2: According to the collected data, perform energy optimization scheduling through the Energy Management System (EMS), give priority to using photovoltaic power generation, and store the excess electric energy in the battery pack;

[0045] Step 3: Charge during the low grid electricity price period and discharge during the high price period to achieve peak shaving and valley filling;

[0046] Step 4: Switch to the off-grid mode during grid faults to provide backup power for the load;

[0047] Step 5: Real-time display of the system status and energy consumption data through the user interface, and provide remote control functions.

[0048] Preferably, the objective function of the energy optimization scheduling is:

[0049] min(C grid *P grid +C battery *P battery )

[0050] And it satisfies the following constraints:

[0051] P pv +P battery +P grid =P load

[0052] And the constraints on the state of charge (SOC) of the battery: SOC (t)

[0053] SOC min ≤SOC(t)≤SOC max

[0054] Where SOC min and SOC max are the minimum and maximum allowable states of the battery respectively.

[0055] The advantages of the embodiments of this application are:

[0056] 1. Through the intelligent energy management system, the status information of photovoltaic power generation, energy storage, and load is monitored and analyzed in real time, the energy distribution and scheduling strategy is optimized, the use of photovoltaic power generation is prioritized, the excess electric energy is reasonably stored and utilized, the energy utilization efficiency is effectively improved. Compared with the traditional photovoltaic energy storage system, it can make more full use of solar energy resources, reduce the loss of energy in the conversion and transmission process, reduce the dependence on the grid, and thus reduce the electricity cost.

[0057] 2. The system realizes the function of peak shaving and valley filling. According to the peak-valley changes of the grid electricity price, it reasonably arranges the charging and discharging time and power of the energy storage module, charges during the low-price period of the electricity price to reduce the low-load of the grid; discharges during the high-price period of the electricity price to relieve the high-power supply pressure of the grid, effectively balancing the grid load, reducing the peak-valley difference of the grid, which helps to improve the stability and reliability of the grid, reduces the risk of grid failures caused by excessive load fluctuations, and at the same time provides certain auxiliary services for the grid, such as peak regulation, frequency modulation, etc.

[0058] 3. When the grid fails, the system can quickly switch to the off-grid mode, and the energy storage module provides backup power for the load to ensure the continuous operation of important loads, which enhances the reliability and anti-interference ability of the power system, provides a more stable power supply for users. For some places with high requirements for power supply continuity (such as hospitals, data centers, communication base stations, etc.), the backup power function of this system can effectively avoid major losses caused by power outages.

[0059] 4. The user interface is friendly and provides real-time monitoring and remote control functions. Users can view the operating status and energy consumption data of the system at any time through the mobile application or the Web interface, which is convenient for users to understand the energy usage situation and formulate personalized energy-saving strategies. At the same time, the remote control function enables users to control the equipment in the system at different locations, realizing more intelligent energy management. Brief Description of the Drawings

[0060] Figure 1 It is a schematic flow diagram of an integrated photovoltaic energy storage management system and its control method of the present invention. Detailed Embodiments

[0061] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. In addition, for the convenience of description below, the "upper", "lower", "left", "right", etc. cited are consistent with the upper, lower, left, right, etc. of the drawings themselves. The "first", "second", etc. in the following text are for descriptive distinction and have no other special meanings.

[0062] Embodiments of the present application provide an integrated photovoltaic energy storage management system and its control method to solve the problems in the prior art. Through an intelligent energy management system, the status information of photovoltaic power generation, energy storage, and load is monitored and analyzed in real time, the energy distribution and scheduling strategy are optimized, photovoltaic power generation is preferentially used, and redundant electric energy is reasonably stored and utilized, effectively improving the energy utilization efficiency. Compared with traditional photovoltaic energy storage systems, it can make more full use of solar energy resources, reduce energy losses during conversion and transmission, reduce the dependence on the power grid, and thus reduce the electricity cost; the system realizes the function of peak shaving and valley filling. According to the peak-valley changes of the grid electricity price, the charging and discharging time and power of the energy storage module are reasonably arranged, charging during the low electricity price period to reduce the low-load of the grid; discharging during the high electricity price period to relieve the high-power supply pressure of the grid, effectively balancing the grid load, reducing the peak-valley difference of the grid, which helps to improve the stability and reliability of the grid, reduce the risk of grid failures caused by excessive load fluctuations, and at the same time provide certain auxiliary services for the grid, such as peak regulation, frequency modulation, etc.; when the grid fails, the system can quickly switch to the off-grid mode, and the energy storage module provides backup power for the load to ensure the continuous operation of important loads, which enhances the reliability and anti-interference ability of the power system and provides a more stable power supply for users. For some places with high requirements for the continuity of power supply (such as hospitals, data centers, communication base stations, etc.), the backup power function of this system can effectively avoid major losses caused by power outages; the user interface is friendly, providing real-time monitoring and remote control functions. Users can view the operating status and energy consumption data of the system at any time through a mobile application or a Web interface, which is convenient for users to understand the energy usage situation and formulate personalized energy-saving strategies. At the same time, the remote control function enables users to control the devices in the system at different locations, realizing more intelligent energy management.

[0063] The technical solutions in the embodiments of the present application to solve the above problems have the following general ideas:

[0064] Embodiment

[0065] This embodiment provides an integrated photovoltaic energy storage management system and its control method, as Figure 1 shown, including a photovoltaic power generation module, an energy storage module, an energy management module, a grid interaction module, a load management module, a communication and control system, and a user interface; among them,

[0066] The photovoltaic power generation module includes photovoltaic components and an inverter, and is used to convert solar energy into electrical energy;

[0067] Among them, the photovoltaic module is the core component for realizing photoelectric conversion. Based on the photovoltaic effect, it converts solar photons into electrons, thereby generating direct current. Different types of photovoltaic modules (such as monocrystalline silicon, polycrystalline silicon, thin-film photovoltaic modules, etc.) have different photoelectric conversion efficiencies and characteristics, and can be selected according to the actual application scenarios and requirements. The inverter is responsible for converting the direct current generated by the photovoltaic module into alternating current that meets the requirements of the power grid or load. Its conversion efficiency and output power quality directly affect the overall performance of the photovoltaic power generation module. For example, by adopting advanced sine pulse width modulation (SPWM) technology or space vector pulse width modulation (SVPWM) technology, the quality of the alternating current output by the inverter can be effectively improved, and the harmonic content can be reduced;

[0068] The energy storage module includes a battery pack and a battery management system (BMS) for storing and releasing electrical energy;

[0069] Among them, the battery pack serves as the carrier for electrical energy storage. Different types of batteries (such as lead-acid batteries, lithium-ion batteries, sodium-sulfur batteries, etc.) have different energy densities, charge and discharge efficiencies, cycle lives, and costs, etc., and need to be selected according to the specific application scenarios and budgets of the system. The BMS is the key control unit of the energy storage module. It real-time monitors various parameters of the battery pack, such as voltage, current, temperature, state of charge (SOC), etc. Through the precise monitoring and analysis of these parameters, the BMS realizes functions such as charge and discharge control, equalization management, and fault diagnosis of the battery pack, ensuring the safe and efficient operation of the battery pack and extending the battery life. For example, when the voltage of a single cell in the battery pack is too high or too low, the BMS can adjust it through the equalization circuit to keep each single cell in a consistent charging state;

[0070] The energy management module includes an energy management system (EMS) for optimizing energy distribution and scheduling;

[0071] Among them, the EMS comprehensively analyzes the data information from the photovoltaic power generation module, the energy storage module, the load management module, and the grid interaction module, and uses advanced optimization algorithms (such as linear programming, dynamic programming, etc.) to make energy optimization distribution and scheduling decisions. For example, according to factors such as real-time light intensity, battery SOC value, load power demand, and grid electricity price, the EMS formulates the optimal power generation, energy storage, and power consumption strategies to ensure the efficient utilization of energy and cost minimization. At the same time, the EMS also has the function of data interaction and instruction transmission with other system modules to realize the coordinated operation of the entire system;

[0072] The grid interaction module includes a grid-connected inverter and a protection device for realizing two-way power exchange with the power grid;

[0073] Among them, the grid-connected inverter is responsible for realizing the bidirectional power exchange with the power grid, delivering the excess electric energy generated by the photovoltaic power generation module to the power grid, and obtaining electric energy from the power grid when needed. To ensure the stability of the grid connection process and the power quality, the grid-connected inverter needs to meet strict grid connection standards, such as requirements for frequency, voltage deviation, harmonic content, etc. The protection device monitors the operating status of the power grid and the system in real time. When abnormal conditions such as overvoltage, undervoltage, overcurrent, and leakage occur, it quickly cuts off the circuit to protect the safety of system equipment and personnel. For example, when the grid voltage exceeds the normal range, the protection device immediately operates to prevent high voltage from damaging the electrical equipment in the system;

[0074] The load management module includes an intelligent load controller for adjusting the load according to the energy supply situation;

[0075] Among them, the controller intelligently adjusts the connected load according to the energy supply situation, such as information on photovoltaic power generation, energy storage battery power, and grid electricity price. For some adjustable loads (such as smart home appliances, industrial equipment, etc.), the intelligent load controller can interact with the load through a communication interface (such as ZigBee, Wi-Fi, Bluetooth, etc.), and adjust the operating power or operating time of the load according to the set strategy. For example, when the photovoltaic power generation is sufficient and the grid electricity price is high, the intelligent load controller can give priority to starting high-power loads to make full use of low-cost photovoltaic power generation; while when the photovoltaic power generation is insufficient or the grid electricity price is low, it appropriately reduces the power of non-critical loads or delays their operating time to achieve reasonable utilization of energy and cost control;

[0076] The communication and control system includes a communication module and a control system for realizing data transmission and instruction execution between modules;

[0077] Among them, the communication module is responsible for realizing data transmission between system modules, ensuring accurate and real-time interaction of information. Multiple communication methods can be used. For example, wired communication (such as RS485, Ethernet, etc.) is suitable for modules with relatively short distances, large data transmission volumes, and high requirements for stability; wireless communication (such as ZigBee, LoRa, 4G / 5G, etc.) is suitable for scenarios with relatively long distances, difficult wiring, or the need for mobility. The control system receives data information from each module and coordinates and controls each module according to the preset control strategy and the instructions of the EMS to ensure the stable operation of the system. For example, when the EMS issues an instruction to adjust the output power of the photovoltaic power generation module, the control system conveys the instruction to the inverter of the photovoltaic power generation module through the communication module to achieve precise adjustment of the power generation power;

[0078] The user interface includes a mobile application and a Web interface for real-time monitoring of the system status and energy consumption data;

[0079] Among them, the mobile application enables users to monitor the system status and energy consumption data anytime and anywhere through mobile devices such as mobile phones and tablets, featuring convenient operation and strong real-time performance. The Web interface provides a more comprehensive and detailed display and management function of system information, which can be accessed by computer browsers and is suitable for scenarios that require in-depth data analysis and system configuration. The user interface not only displays various operating parameters of the system in real time, such as photovoltaic power generation, energy storage battery power, load power, grid interaction power, etc., but also provides a statistical analysis function of energy consumption data to help users understand the energy usage situation and formulate energy-saving strategies. At the same time, users can remotely control some devices (such as intelligent loads, charging devices, etc.) through the user interface to achieve a more intelligent energy management experience.

[0080] The energy management module realizes energy optimization scheduling through the Energy Management System (EMS), and its optimization objective function is:

[0081] min(C grid *P grid +C battery *P battery )

[0082] Among them, C grid is the grid electricity price, P grid is the power obtained from the grid, C battery is the battery charge and discharge cost, and P battery is the battery charge and discharge power.

[0083] The Energy Management System (EMS) needs to meet the following constraints during the scheduling process:

[0084] P pv +P battery +P grid =P load

[0085] Among them, P pv is the photovoltaic power generation, and P load is the load demand power.

[0086] The state of charge (SOC) of the energy storage module's battery is calculated by the following formula:

[0087]

[0088] Among them, SOC(t) is the battery state at the current moment, SOC(t - 1) is the battery state at the previous moment, Δt is the time interval, and E max is the maximum capacity of the battery.

[0089] The output power P inv of the grid-connected inverter in the grid interaction module satisfies the following relationship:

[0090] P inv = η * P DC

[0091] where η is the inverter efficiency and P DC is the DC input power.

[0092] The load priority control strategy of the load management module is implemented by the following formula:

[0093] P critical ≤ P pv + P battery + P grid

[0094] where P critical is the power demand of the critical load.

[0095] The user interface displays the energy balance state of the system in real time, and its energy balance formula is:

[0096] E pv + E battery + E grid = E load

[0097] where E pv is the photovoltaic power generation energy, E battery is the battery charge and discharge energy, E grid is the grid interaction energy, and E load is the load consumption energy.

[0098] It includes the following steps:

[0099] Step 1: Collect photovoltaic power generation data, energy storage status, load demand, and grid information in real time. Among them, various sensors are used to collect photovoltaic power generation data (such as output voltage, current, power, light intensity, etc. of photovoltaic modules), energy storage status (such as battery pack voltage, current, temperature, SOC, etc.), load demand (such as load power, type, operating status, etc.), and grid information (such as grid voltage, frequency, electricity price, etc.). These sensors are distributed at various key positions in the system to ensure the accuracy and real-time nature of the collected data. For example, voltage and current sensors are installed at the output end of the photovoltaic modules to monitor the power generation of the photovoltaic modules in real time; temperature sensors and power sensors are installed in the battery pack to accurately obtain the status information of the battery. The collected data is transmitted to the EMS of the energy management module through the communication module for processing;

[0100] Step 2: According to the collected data, perform energy optimization scheduling through the Energy Management System (EMS). Give priority to using photovoltaic power generation, and store the excess electric energy in the battery pack. Among them, the EMS performs energy optimization scheduling by using an optimization algorithm based on the collected data. First, give priority to using photovoltaic power generation to meet the local load demand. When the photovoltaic power generation is greater than the load demand, store the excess electric energy in the battery pack to improve the self-sufficiency rate of energy. For example, through the real-time monitoring and analysis of the output power of photovoltaic modules, load power, and battery SOC value, the EMS calculates the amount of electric energy that can be stored and sends a charging instruction to the BMS of the energy storage module to control the charging process of the battery pack and ensure the safety and efficiency of the charging process;

[0101] Step 3: Charge during the low grid electricity price period and discharge during the high price period to achieve peak shaving and valley filling. Among them, considering the peak-valley changes of the grid electricity price, the EMS formulates corresponding charge-discharge strategies. During the low grid electricity price period, control the energy storage module to charge from the grid and store the low-price electric energy; during the high electricity price period, control the energy storage module to discharge to the load and reduce the electricity purchase from the grid, thereby achieving peak shaving and valley filling and reducing the electricity cost. For example, by obtaining real-time electricity price information through communication with the grid, combining the battery SOC value and load demand prediction, the EMS plans the charge-discharge time and power of the energy storage module in advance to achieve the best economic benefits. At the same time, this peak shaving and valley filling operation helps to balance the grid load, reduce the peak-valley difference of the grid, and improve the stability and reliability of the grid;

[0102] Step 4: When there is a grid fault, switch to the off-grid mode to provide backup power for the load. Among them, monitor the grid status in real time. When a grid fault (such as power outage, abnormal voltage, abnormal frequency, etc.) is detected, the control system quickly switches to the off-grid mode. In the off-grid mode, the energy storage module serves as a backup power source to provide power support for the load and ensure the continuous operation of important loads. For example, through voltage and frequency monitoring devices installed at the grid access end, monitor the grid parameters in real time. Once a grid fault signal is detected, the control system immediately cuts off the connection with the grid and starts the circuit for the energy storage module to supply power to the load. At the same time, adjust the output voltage and frequency of the energy storage module to match the requirements of the load. In the off-grid mode, the EMS continues to monitor and manage the power of the energy storage module, reasonably allocate electric energy according to the load demand, and ensure that the backup power source can continuously and stably supply power to the load until the grid returns to normal or the power of the energy storage module is exhausted;

[0103] Step 5: Real-time display of the system status and energy consumption data through the user interface, and provide remote control functions. Among them, the system status (such as the operating parameters and working modes of each module) and energy consumption data (such as the daily, weekly, and monthly power generation, power consumption, and energy storage power changes) are displayed in real time through the user interface. Users can intuitively understand the operation of the system and promptly discover potential problems. At the same time, the user interface provides remote control functions. Users can remotely send instructions through a mobile application or a Web interface to control some devices in the system (such as intelligent loads, charging devices, etc.). For example, when users are away, they can view the operation status of the home photovoltaic energy storage system through the mobile application on their mobile phones. If they find that the photovoltaic power generation is sufficient and the energy storage battery is full, they can remotely start the intelligent appliances at home to make full use of the excess electric energy.

[0104] The objective function of the energy optimization scheduling is:

[0105] min(C grid *P grid +C battery *P battery )

[0106] And it satisfies the following constraints:

[0107] P pv +P battery +P grid =P load

[0108] And the constraints on the state of charge (SOC) of the battery: SOC (t)

[0109] SOC min ≤SOC(t)≤SOC max

[0110] Where SOC min and SOC max are the minimum and maximum allowable states of the battery respectively.

[0111] By adopting the above technical solutions:

[0112] Real-time collect photovoltaic power generation data, energy storage status, load demand, and grid information; according to the collected data, perform energy optimization scheduling through an Energy Management System (EMS), giving priority to using photovoltaic power generation, and storing the excess electric energy in the battery pack; charge during the low grid electricity price period and discharge during the high price period to achieve peak shaving and valley filling; when the grid fails, switch to the off-grid mode to provide backup power for the load; display the system status and energy consumption data in real time through the user interface, and provide remote control functions. Through the intelligent energy management system, real-time monitor and analyze the status information of photovoltaic power generation, energy storage, and load, optimize the energy distribution and scheduling strategy, give priority to using photovoltaic power generation, reasonably store and utilize the excess electric energy, effectively improve the energy utilization efficiency. Compared with the traditional photovoltaic energy storage system, it can make more full use of solar energy resources, reduce the loss of energy during conversion and transmission, reduce the dependence on the grid, and thus reduce the electricity cost.

[0113] Finally, it should be noted that: Obviously, the above embodiments are only examples for clearly illustrating the present invention, rather than limiting the implementation manners. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. An integrated photovoltaic energy storage management system, characterized in that: It includes a photovoltaic power generation module, an energy storage module, an energy management module, a grid interaction module, a load management module, a communication and control system, and a user interface; wherein the photovoltaic power generation module includes a photovoltaic component and an inverter, which is used to convert solar energy into electrical energy; The energy storage module includes a battery pack and a battery management system (BMS) for storing and releasing electrical energy; The energy management module includes an energy management system (EMS) for optimizing energy distribution and scheduling; The grid interaction module includes a grid-connected inverter and a protection device for realizing bidirectional power exchange with the grid; The load management module includes an intelligent load controller for adjusting the load according to the energy supply situation; The communication and control system includes a communication module and a control system for realizing data transmission and instruction execution between modules; The user interface includes a mobile application and a web interface for real-time monitoring of system status and energy consumption data.

2. An integrated photovoltaic energy storage management system as claimed in claim 1, characterized in that: The energy management module realizes energy optimization scheduling through the energy management system (EMS), and its optimization objective function is: min(C grid *P grid +C battery *P battery ) Among them, C grid is the grid electricity price, P grid is the power obtained from the grid, C battery is the battery charging and discharging cost, P battery It is the battery charging and discharging power.

3. An integrated photovoltaic energy storage management system as claimed in claim 1, characterized in that: The energy management system (EMS) must meet the following constraints during the scheduling process: P pv +P battery +P grid =P load Among them, P pv is the photovoltaic power generation power, P load The power demanded by the load.

4. An integrated photovoltaic energy storage management system as claimed in claim 1, characterized in that: The battery charge and discharge state (SOC) of the energy storage module is calculated by the following formula: Among them, SOC(t) is the battery state at the current moment, SOC(t-1) is the battery state at the previous moment, Δt is the time interval, E max The maximum capacity of the battery.

5. The integrated photovoltaic energy storage management system according to claim 1, characterized in that: The grid-connected inverter output power P of the grid interaction module inv The following relations are satisfied: P.S inv Hη*P DC Where, η is the inverter efficiency, P DC is the DC input power.

6. An integrated photovoltaic energy storage management system as claimed in claim 1, characterized in that: The load priority control strategy of the load management module is implemented by the following formula: P critical ≤P pv +P battery +P grid Among them, P critical The power requirements of the critical loads.

7. An integrated photovoltaic energy storage management system as claimed in claim 1, characterized in that: The user interface displays the energy balance state of the system in real time, and the energy balance formula is: AND pv +E battery +E grid =And load Among them, E pv is the photovoltaic power generation energy, E battery is the battery charging and discharging energy, E grid is the grid interaction energy, E load Consumes energy for the load.

8. A control method for an integrated photovoltaic energy storage management system, characterized in that: The following steps are involved: Step 1: Collect photovoltaic power generation data, energy storage status, load demand and grid information in real time; Step 2: Based on the collected data, the energy management system (EMS) is used to optimize energy scheduling, giving priority to photovoltaic power generation, and storing excess power in the battery pack; Step 3: Charge when the power grid electricity price is low, and discharge when the power grid electricity price is high, so as to achieve peak load shifting; Step 4: When the power grid fails, switch to off-grid mode to provide backup power for the load; Step 5: Display system status and energy consumption data in real time through the user interface and provide remote control function.

9. A control method for an integrated photovoltaic energy storage management system according to claim 8, characterized in that: The objective function of the energy optimization scheduling is: min(C grid *P grid +C battery *P battery ) And satisfy the following constraints: P pv +P battery +P grid =P load And the constraints of battery charge and discharge state (SOC): SOC (t) SOC min ≤SOC(t)≤SOC max Among them, SOC min and SOC max are the minimum and maximum allowed states of the battery, respectively.

Images