A photovoltaic energy storage AC / DC hybrid microgrid system

Abstract

The present invention relates to the field of microgrid technology, and specifically to a photovoltaic storage AC / DC hybrid microgrid system. The photovoltaic storage AC / DC hybrid microgrid system provided by the embodiment of the present invention is a highly integrated comprehensive energy system, which integrates photovoltaic power generation, energy storage technology, AC / DC power conversion and intelligent management technology. The system realizes unified coordination and management of photovoltaic power generation, energy storage, energy conversion, energy management, monitoring and protection, and load modules through a microgrid controller. The introduction of a wireless transmission module ensures the real-time transmission of information between modules within the system and the rapid execution of instructions, thereby improving the response speed and reliability of the system. In addition, the modular design enables the system to be flexibly expanded and upgraded according to actual needs, enhancing the flexibility, adaptability and scalability of the system. Overall, the system efficiently coordinates energy utilization, has strong real-time communication capabilities, and is highly flexible and scalable.

Description

Technical Field

[0001] The present invention relates to the technical field of microgrids, and in particular to a photovoltaic-storage AC / DC hybrid microgrid system. Background Art

[0002] The photovoltaic-storage AC / DC hybrid microgrid system is a small-scale power generation and distribution system that integrates photovoltaic power generation, energy storage technology and AC / DC hybrid microgrid technology. At present, AC microgrids are still the main form of microgrids. Although many achievements have been made in the research of AC microgrids, it is still necessary to further solve the effects of resonance, harmonics, etc. caused by the parallel connection of distributed power sources.

[0003] Compared with AC microgrid, DC microgrid system does not need to consider the synchronization problem between distributed power sources, and has more advantages in circulating current suppression. In addition, DC microgrid only needs to use inverters at the connection with the main grid, which greatly reduces system cost and loss. At present, the concept of smart grid is deeply rooted in people's hearts, and its construction concept is to provide reliable and high-quality electricity for the digital society in an environmentally friendly and sustainable way. The most important feature of smart grid is that it can connect various AC and DC power generation systems, energy storage systems and various AC and DC loads to achieve optimal operating efficiency.

[0004] However, in the current smart grids, the access of distributed power sources often lacks unified planning and effective management, resulting in low energy utilization efficiency and poor system stability. Summary of the invention

[0005] In view of this, an embodiment of the present invention provides a photovoltaic energy storage AC / DC hybrid microgrid system to solve the technical problems of low energy utilization efficiency and poor system stability of smart grids in the prior art.

[0006] The technical solution provided by the embodiment of the present invention is as follows:

[0007] A first aspect of an embodiment of the present invention provides a photovoltaic storage AC / DC hybrid microgrid system, the system comprising: a distribution network, a microgrid controller, a wireless transmission module, an optimization module, a photovoltaic power generation module, an energy storage module, an energy conversion module, an energy management module, a monitoring and protection module, and a load module; the distribution network is used to receive external input electric energy for conversion and distribution; the microgrid controller is used to coordinate and control the optimization module, the photovoltaic power generation module, the energy storage module, the energy conversion module, the energy management module, and the load module through the wireless transmission module based on the electric energy distributed by the distribution network; the photovoltaic power generation module is used to convert solar energy into electric energy; the energy storage module The module is used for storing and releasing electric energy; the energy conversion module is used for converting between direct current and alternating current; the energy management module is connected to the photovoltaic power generation module, the energy storage module and the energy conversion module, and is used to manage and control the electric energy conversion of the photovoltaic power generation module, the energy storage module and the energy conversion module; the load module is connected to the photovoltaic power generation module, the energy storage module and the energy conversion module, and is used to dispatch the electric energy output by the photovoltaic power generation module, the energy storage module and the energy conversion module according to the load demand; the monitoring and protection module is used to monitor and protect the photovoltaic power generation module, the energy storage module, the energy conversion module and the energy management module. The optimization module is used to optimize the operation of the photovoltaic power generation module, the energy storage module, the energy conversion module, the energy management module and the monitoring and protection module.

[0008] In an optional embodiment, the photovoltaic power generation module includes a photovoltaic panel module, a photovoltaic inverter module, a photovoltaic regulation module and a light intensity sensor module; the photovoltaic panel module is used to convert solar energy into electrical energy; the photovoltaic inverter module is used to convert the electrical energy converted by the photovoltaic power generation module into alternating current; the light intensity sensor module is used to monitor light intensity; the photovoltaic regulation module is used to regulate the photovoltaic panel module according to the regulation signal generated by the microgrid controller based on the light intensity.

[0009] In an optional embodiment, the energy storage module includes a battery module, a battery management module, a charge and discharge control module and a communication interface module; the battery module is used to store and release electric energy; the battery management module is used to fine-tune the working state of the battery module according to the working parameters of the battery module; the communication interface module is used to connect to the microgrid controller through the wireless transmission module and receive the control signal of the microgrid controller; the charge and discharge control module is used to control the charge and discharge of the battery module according to the control signals of the microgrid controller, the energy management module and the monitoring and protection module.

[0010] In an optional embodiment, the energy conversion module includes a rectifier module, a photovoltaic inverter module, a DC / DC converter, a power electronic switch and a filtering and regulating module; the rectifier module is used to convert the AC power distributed by the distribution network into DC power; the photovoltaic inverter module is used to convert the DC power generated by the photovoltaic power generation module into AC power; the DC / DC converter is used to adjust the conversion between different DC voltage levels; the power electronic switch is used to switch the circuits in the photovoltaic power generation module and the energy storage module according to the instructions of the microgrid controller and the protection signal of the monitoring and protection module; the filtering and regulating module is used to eliminate the harmonics and noise generated during the power conversion process.

[0011] In an optional embodiment, the energy management module includes a maximum power point tracking control module, an SOC limit management control module, a hybrid energy storage system energy management control module, a centralized control module, a data monitoring module and an intelligent prediction module; the maximum power point tracking control module is used to adjust the operating point of the photovoltaic power generation module; the SOC limit management control module is used to optimize the charging and discharging of the energy storage module according to the energy storage medium; the hybrid energy storage system energy management control module includes a battery and a supercapacitor, which is used to realize power distribution between the battery and the supercapacitor according to a first-order low-pass filtering algorithm; the data monitoring module is used to obtain operating data of the photovoltaic power generation module, the energy storage module and the energy conversion module; the centralized control module is used to perform safety hazard analysis based on the operating data; the intelligent prediction module is used to predict the operation of the energy storage module, and optimize the charging and discharging of the energy storage module based on the prediction results.

[0012] In an optional embodiment, the load module includes a DC load module, an AC load module and a load controller module; the load controller module is used to generate a load management strategy according to the instructions of the microgrid controller, the external power demand and the priority of the load device; the DC load module is used to schedule the power output by the photovoltaic power generation module, the energy storage module and the energy conversion module according to the load management strategy, and adjust the operating state of the external DC load; the AC load module is used to schedule the power output by the photovoltaic power generation module, the energy storage module and the energy conversion module according to the load management strategy, and adjust the operating state of the external AC load.

[0013] In an optional embodiment, the monitoring and protection module includes a temperature monitoring module, an overcurrent protection module, an overvoltage protection module and an undervoltage protection module; the temperature monitoring module is used to perform temperature monitoring, and performs temperature protection when the temperature is higher than a temperature threshold; the overcurrent protection module is used to perform current monitoring, and performs overcurrent protection when the current is higher than a current threshold; the overvoltage protection module is used to perform voltage monitoring, and performs overvoltage protection when the voltage is higher than a first voltage threshold; the undervoltage protection module is used to perform voltage monitoring, and performs undervoltage protection when the voltage is lower than a second voltage threshold.

[0014] In an optional implementation, the monitoring and protection module further includes an alarm module and a positioning module; the positioning module is used to locate the fault using positioning technology; and the alarm module is used to issue an alarm according to the fault location result.

[0015] In an optional embodiment, the optimization module includes: an intelligent integration module, an intelligent operation and maintenance module, and an advanced control and protection module; the intelligent integration module is used to adopt the Internet of Things technology to realize data transmission in the system through communication modules and communication protocols; the intelligent operation and maintenance module is used for fault prediction and automated inspection and fault handling; the advanced control and protection module is connected to the monitoring and protection module for fault protection based on control algorithms and protection technologies.

[0016] In an optional embodiment, the optimization module also includes: an energy storage enhancement module, a stability enhancement module and a grid-connected optimization module; the energy storage enhancement module is connected to the energy storage module, and is used to obtain new energy storage materials and technologies and a battery management system to optimize the configuration of the energy storage module; the stability enhancement module is used to obtain new power equipment and control algorithms to enhance the stability of the system; the grid-connected optimization module system is used to obtain new power equipment, control strategies and power management strategies to optimize the system grid connection.

[0017] The technical solution of the present invention has the following advantages:

[0018] The photovoltaic-storage AC / DC hybrid microgrid system provided in the embodiment of the present invention is a highly integrated comprehensive energy system, which integrates photovoltaic power generation, energy storage technology, AC / DC power conversion and intelligent management technology. The system realizes unified coordination and management of photovoltaic power generation, energy storage, energy conversion, energy management, monitoring and protection, and load modules through a microgrid controller. The introduction of the wireless transmission module ensures the real-time transmission of information and the rapid execution of instructions between modules within the system, thereby improving the response speed and reliability of the system. In addition, the modular design enables the system to be flexibly expanded and upgraded according to actual needs, enhancing the flexibility, adaptability and scalability of the system. Overall, the system efficiently coordinates energy utilization, has strong real-time communication capabilities, and is highly flexible and scalable.

[0019] In this embodiment, the photovoltaic storage AC / DC hybrid microgrid system realizes intelligent management of photovoltaic power generation modules, energy storage modules and load modules through its energy management module. The energy management module includes a maximum power point tracking control module, an SOC limit management control module, a hybrid energy storage system energy management control module, etc., which can perform intelligent prediction and optimized scheduling based on real-time data to ensure efficient utilization of energy and stable operation of the system. Through intelligent prediction and optimized scheduling, the system can make full use of photovoltaic energy, reduce energy waste and improve energy utilization. The introduction of the hybrid energy storage system can provide stable power support during peak load or fault conditions of the power grid, ensure stable operation of the system, and enhance system stability. Through intelligent management and optimized scheduling, the system can reduce unnecessary energy consumption and equipment wear, thereby reducing operating costs.

[0020] In this embodiment, the monitoring and protection module is an important component of the photovoltaic energy storage AC / DC hybrid microgrid system. It monitors the operating status and parameters of each device in real time, and ensures the safe and stable operation of the system through temperature monitoring, overcurrent, overvoltage, undervoltage and other protection modules. Once a fault or abnormal situation occurs, the module can quickly locate and alarm, reduce the impact of the fault, and improve system safety. At the same time, real-time monitoring and fault recording functions facilitate system maintenance, reduce maintenance costs and time, and thus reduce fault losses.

[0021] In this embodiment, the intelligent integration module solves the technical compatibility and interface matching problems in system integration, realizes communication and protocol conversion between devices, and automates configuration and debugging to reduce manual intervention and improve integration efficiency. The advanced control and protection module adopts advanced algorithms and strategies to monitor the operating status in real time and respond to abnormalities quickly. The collaborative energy management module optimizes system operation. The energy storage enhancement module adopts new energy storage technology, intelligently manages energy storage equipment, and obtains prediction technology to optimize scheduling. The stability enhancement module applies power electronics technology and control strategies to improve system stability, monitor and deal with unstable factors in real time. The grid optimization module develops DC grid connection technology to ensure the system grid connection efficiency and stability and realize two-way interaction with the power grid. The intelligent operation and maintenance module uses the Internet of Things, big data and AI technologies to realize intelligent operation and maintenance management, monitor equipment status in real time, predict faults and perform maintenance in advance, reduce operation and maintenance costs, and improve management efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a structural block diagram of a photovoltaic-storage AC-DC hybrid microgrid system in an embodiment of the present invention;

[0024] Figure 2 Schematic diagram of the connection structure of each module in the photovoltaic power generation module in an embodiment of the present invention;

[0025] Figure 3 Schematic diagram of the connection structure of each module in the energy storage module in an embodiment of the present invention;

[0026] Figure 4 This is a schematic diagram of the connection structure of each module in the energy conversion module in an embodiment of the present invention;

[0027] Figure 5 This is a schematic diagram of the connection structure of each module in the energy management module in an embodiment of the present invention;

[0028] Figure 6 This is a schematic diagram of the connection structure of each module in the load module in an embodiment of the present invention;

[0029] Figure 7 This is a schematic diagram of the connection structure of each module in the monitoring and protection module in an embodiment of the present invention;

[0030] Figure 8 Schematic diagram of the connection structure of each module in the optimization module in an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0033] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, it can also be the internal connection of two components, it can be a wireless connection, or it can be a wired connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0035] The embodiment of the present invention provides a photovoltaic storage AC / DC hybrid microgrid system, such as Figure 1 As shown, the system includes: a distribution network, a microgrid controller, a wireless transmission module, an optimization module, a photovoltaic power generation module, an energy storage module, an energy conversion module, an energy management module, a monitoring and protection module, and a load module; the distribution network is used to receive external input electric energy for conversion and distribution; the microgrid controller is used to coordinate and control the optimization module, the photovoltaic power generation module, the energy storage module, the energy conversion module, the energy management module, and the load module through the wireless transmission module based on the electric energy distributed by the distribution network; the photovoltaic power generation module is used to convert solar energy into electric energy; the energy storage module is used to store and release electric energy ; The energy conversion module is used for the conversion between direct current and alternating current; the energy management module is connected to the photovoltaic power generation module, the energy storage module and the energy conversion module, and is used to manage and control the power conversion of the photovoltaic power generation module, the energy storage module and the energy conversion module; the load module is connected to the photovoltaic power generation module, the energy storage module and the energy conversion module, and is used to dispatch the power output of the photovoltaic power generation module, the energy storage module and the energy conversion module according to the load demand; the monitoring and protection module is used to monitor and protect the photovoltaic power generation module, the energy storage module, the energy conversion module and the energy management module. The optimization module is used to optimize the operation of the photovoltaic power generation module, the energy storage module, the energy conversion module, the energy management module and the monitoring and protection module.

[0036] Specifically, the distribution network includes overhead lines, poles, cables, distribution transformers, switchgear, reactive compensation capacitors and other distribution equipment and ancillary facilities, which can realize energy conversion and distribution. The microgrid controller is the core of the entire system, which connects signals with various modules and modules through wireless transmission modules to achieve coordination and management. The energy conversion module realizes the conversion between direct current and alternating current, and the energy management module uniformly manages and dispatches the system energy. The monitoring and protection module monitors the operating status and parameters of each module and module in the system in real time to ensure the safe and stable operation of the system. The load module is responsible for the intelligent management and dispatching of the load to ensure the rational distribution and utilization of energy. The optimization module improves the energy utilization efficiency and system stability. The entire system achieves efficient energy utilization and stable system operation through intelligent management.

[0037] The management and control of the energy management module includes intelligent prediction and optimal scheduling of energy, such as prediction of load demand, renewable energy production, energy storage status, etc., and optimization decisions based on these predictions. Algorithms such as linear programming, dynamic programming, and machine learning can be used for prediction and scheduling. For example, the energy balance formula shown below can be used for scheduling:

[0038] E_{stored} = E_{produced} - E_{consumed}

[0039] Among them, (E_{stored}) is the stored energy of the energy storage module, (E_{produced}) is the produced energy, and (E_{consumed}) is the consumed energy.

[0040] In an optional embodiment, the photovoltaic power generation module includes a photovoltaic panel module, a photovoltaic inverter module, a photovoltaic regulation module and a light intensity sensor module; the photovoltaic panel module is used to convert solar energy into electrical energy; the photovoltaic inverter module is used to convert the electrical energy converted by the photovoltaic power generation module into alternating current; the light intensity sensor module is used to monitor light intensity; and the photovoltaic regulation module is used to regulate the photovoltaic panel module according to a regulation signal generated by a microgrid controller based on light intensity.

[0041] Specifically, Figure 2As shown, the photovoltaic panel module, photovoltaic inverter module, photovoltaic regulation module and light intensity sensor module are connected through the wireless transmission module and the microgrid controller signal. The photovoltaic power generation module in the photovoltaic storage AC / DC hybrid microgrid system is a key component. Among them, the photovoltaic panel module includes multiple photovoltaic arrays, which can capture and convert the solar energy irradiated thereon into direct current; the photovoltaic inverter module converts direct current into alternating current so as to better access and meet the power demand in the microgrid; the light intensity sensor module monitors the light intensity in the environment in real time and provides accurate data support for the photovoltaic regulation module. The photovoltaic regulation module adjusts the working state, position and angle of the photovoltaic panel module according to system requirements and environmental conditions to ensure its efficient and stable operation. For example, the orientation, angle and other parameters of the photovoltaic panel module can be adjusted to maximize its efficiency in receiving solar energy; in this embodiment, by real-time perception of changes in light intensity, the working state of the photovoltaic panel can be adjusted more accurately to further improve the energy conversion efficiency. These sub-modules are connected to the microgrid controller through a wireless transmission module to realize real-time transmission of information and rapid execution of instructions. The microgrid controller can coordinate and manage the photovoltaic power generation module according to the data and instructions of each module to ensure that it operates in the best state and provide stable and reliable power support for the entire microgrid system.

[0042] In an optional embodiment, the energy storage module includes a battery module, a battery management module, a charge and discharge control module and a communication interface module; the battery module is used to store and release electric energy; the battery management module is used to fine-tune the working state of the battery module according to the working parameters of the battery module; the communication interface module is used to connect to the microgrid controller through the wireless transmission module and receive the control signal of the microgrid controller; the charge and discharge control module is used to control the charge and discharge of the battery module according to the control signals of the microgrid controller, the energy management module and the monitoring and protection module.

[0043] Specifically, Figure 3As shown, the battery module, battery management module, charge and discharge control module and communication interface module are connected to the microgrid controller signal through the wireless transmission module, and the charge and discharge control module is connected to the energy management module and the monitoring and protection module signal through the wireless transmission module. The battery module is the core of the energy storage module. It is responsible for storing electrical energy and releasing it when needed. The battery management module monitors and manages the battery in real time to ensure that the battery operates in a safe and efficient state, such as monitoring the battery's voltage, current, temperature and other parameters, and adjusting the battery's working state according to these parameters. The charge and discharge control module controls the battery's charge and discharge process. According to the instructions issued by the microgrid controller, it controls the battery's charge and discharge current to ensure the power balance and bus voltage stability of the microgrid system. In addition, the charge and discharge control module also connects the energy management module and the monitoring and protection module through the wireless transmission module to receive their instructions and data to achieve more accurate charge and discharge control. The communication interface module is a bridge for the energy storage module to communicate with the microgrid controller. It connects the microgrid controller through the wireless transmission module to achieve real-time data transmission and rapid execution of instructions, which enables the microgrid controller to monitor the working state of the energy storage module in real time and adjust and optimize it as needed. The energy storage module realizes intelligent management and optimized scheduling of electric energy through the collaboration between its various sub-modules and communication with the microgrid controller.

[0044] In an optional embodiment, the energy conversion module includes a rectifier module, a photovoltaic inverter module, a DC / DC converter, a power electronic switch and a filtering and regulating module; the rectifier module is used to convert the AC power distributed by the distribution network into DC power; the photovoltaic inverter module is used to convert the DC power generated by the photovoltaic power generation module into AC power; the DC / DC converter is used to adjust the conversion between different DC voltage levels; the power electronic switch is used to switch the circuits in the photovoltaic power generation module and the energy storage module according to the instructions of the microgrid controller and the protection signal of the monitoring and protection module; the filtering and regulating module is used to eliminate the harmonics and noise generated during the power conversion process.

[0045] Specifically, Figure 4 As shown, the rectifier module, the photovoltaic inverter module, the DC / DC converter, the power electronic switch and the filter regulation module are connected to the microgrid controller signal through the wireless transmission module, the energy conversion module and the energy storage module are electrically connected, the energy conversion module is connected to the monitoring and protection module signal through the wireless transmission module, and the signal is connected to the microgrid controller through the wireless transmission module to achieve accurate power conversion and distribution.

[0046] Among them, the rectifier module converts AC power into DC power to provide a stable power supply for DC devices in the system; the photovoltaic inverter module converts the DC power generated by the photovoltaic panel module into AC power for access to the power grid or for use by AC devices; the DC / DC converter is used to adjust the conversion between different DC voltage levels to meet the needs of different equipment; the power electronic switch is a key component in the energy conversion module. It switches the circuit quickly and accurately according to the instructions of the microgrid controller to achieve precise control of electric energy; the filter regulation module is used to eliminate the harmonics and noise generated during the power conversion process to ensure the quality of electric energy. The energy conversion module is electrically connected to the energy storage module, which can realize the charging and discharging management of the electric energy in the energy storage module. Through the instructions of the microgrid controller, the energy conversion module can control the charging and discharging process of the energy storage module to ensure the power balance and bus voltage stability of the microgrid system. In addition, the energy conversion module is also connected to the monitoring and protection module through a wireless transmission module. The monitoring and protection module can monitor the operating status and parameters of the energy conversion module in real time, and take protective measures when a fault or abnormal situation occurs. This real-time monitoring and protection mechanism can ensure the safe and stable operation of the energy conversion module and improve the reliability of the entire microgrid system.

[0047] In an optional implementation, the energy management module includes a maximum power point tracking control module, an SOC limit management control module, a hybrid energy storage system energy management control module, a centralized control module, a data monitoring module and an intelligent prediction module; the maximum power point tracking control module is used to adjust the operating point of the photovoltaic power generation module; the SOC limit management control module is used to optimize the charging and discharging of the energy storage module according to the energy storage medium; the hybrid energy storage system energy management control module includes a battery and a supercapacitor, which is used to realize power distribution between the battery and the supercapacitor according to a first-order low-pass filtering algorithm; the data monitoring module is used to obtain operating data of the photovoltaic power generation module, the energy storage module and the energy conversion module; the centralized control module is used to perform safety hazard analysis based on the operating data; the intelligent prediction module is used to predict the operation of the energy storage module, and optimize the charging and discharging of the energy storage module based on the prediction results.

[0048] Specifically, Figure 5 As shown, the maximum power point tracking control module, the SOC limit management control module, the hybrid energy storage system (HESS) energy management control module, the centralized control module, the data monitoring module and the intelligent prediction module are connected to the microgrid controller module signal through the wireless transmission module, and the energy management module and the energy storage module signal are connected.

[0049] Among them, the maximum power point tracking control module maximizes the output power of the photovoltaic panel by adjusting the working point of the photovoltaic array in the photovoltaic panel module, thereby making full use of solar energy resources. The SOC limit management control module optimizes the hybrid energy storage power distribution according to the different characteristics of the energy storage medium, and further optimizes the battery charging and discharging process. This module can avoid overcharging and over-discharging of energy storage equipment and ensure stable operation of the system. The energy management control module of the hybrid energy storage system is the key to achieving energy management in the photovoltaic storage DC microgrid. It uses a combination of batteries and supercapacitors to form a hybrid energy storage system, and realizes power distribution between the two energy storage media through a first-order low-pass filtering algorithm. Among them, the battery responds to the low-frequency part of the target power, while the supercapacitor responds to the high-frequency part of the target power, and finally achieves tracking response to the target power.

[0050] The data monitoring module monitors the operating status and parameters of each device in the microgrid system in real time, and sends these data to the centralized control module through the signal transmission module. The centralized control module is the "brain" of the energy management module. It connects the microgrid controller with the signal through the wireless transmission module, receives and processes the data and instructions from each module, and realizes the centralized management and control of the entire microgrid system through data analysis. It can timely discover and solve potential safety hazards and improve the safety and stability of the system. The intelligent prediction module uses the algorithms in related technologies to predict the energy demand of the system and the status of the energy storage module. Based on the prediction results, the energy management strategy can be formulated in advance to optimize the charging and discharging process of the energy storage module and improve the energy utilization efficiency of the system. The signal connection between the energy management module and the energy storage module ensures that the charging and discharging process of the energy storage device is precisely controlled. According to the instructions of the centralized control module and the data feedback of the data monitoring module, the energy management module can adjust the charging and discharging strategy of the energy storage device in real time to ensure the power balance and bus voltage stability of the microgrid system.

[0051] The maximum power point tracking control module can use the maximum power point tracking (MPPT) algorithm to adjust the working point. The maximum power point tracking control module uses MPPT algorithms such as Perturb and Observe algorithms (P&O) and Incremental Conductance (Incremental Conductance, IncCond) to track the maximum power point of the photovoltaic cell in real time and adjust the working voltage or current of the photovoltaic cell to maximize the output power.

[0052] The P&O algorithm is implemented using the following formula:

[0053] V_{new} = V_{old} + \Delta V

[0054] P_{new} = V_{new} \times I_{new}

[0055] Where V_{old} and V_{new} are the operating voltages of the photovoltaic cell, \Delta V is the voltage adjustment step, and I_{new} is the corresponding new operating current.

[0056] In an optional implementation, the load module includes a DC load module, an AC load module and a load controller module; the load controller module is used to generate a load management strategy according to the instructions of the microgrid controller, the external power demand and the priority of the load device; the DC load module is used to schedule the power output by the photovoltaic power generation module, the energy storage module and the energy conversion module according to the load management strategy, and adjust the operating state of the external DC load; the AC load module is used to schedule the power output by the photovoltaic power generation module, the energy storage module and the energy conversion module according to the load management strategy, and adjust the operating state of the external AC load.

[0057] Specifically, Figure 6 As shown, the DC load module, AC load module and load controller module are all connected to the microgrid controller through the wireless transmission module, and the DC load module, AC load module and load controller module are electrically connected to the energy conversion module. Among them, the load controller module is the core part of the load module. It is connected to the microgrid controller through the wireless transmission module, receives and processes the instructions from the microgrid controller, and the load controller module also formulates the load management strategy according to the power demand of the system and the priority of the load equipment, and sends the instructions to the DC load module and the AC load module through the electrical connection to realize the intelligent management and scheduling of the load equipment. The DC load module connects and manages DC load equipment, such as DC motors, LED lighting, etc., adjusts the operating status of the DC load equipment according to the instructions, and realizes the reasonable distribution of electric energy. The AC load module connects and manages AC load equipment, such as household appliances, industrial equipment, etc. Similarly, it controls the AC load equipment to meet the power demand of different equipment.

[0058] In addition, the load module is electrically connected to the energy conversion module to ensure that after the electric energy passes through the energy conversion module from the energy storage module or the photovoltaic power generation module, it can be supplied to the DC load module or the AC load module according to the requirements of the load module. This connection method enables the system to flexibly adjust the distribution of electric energy to meet the needs of different load devices. The load module plays an important role in the photovoltaic storage AC / DC hybrid microgrid system. It realizes intelligent management and scheduling of load devices through the coordinated work of the DC load module, the AC load module and the load controller module, ensuring the reasonable distribution and efficient utilization of electric energy. At the same time, the electrical connection with the energy conversion module enables the system to flexibly adjust the distribution of electric energy to meet the needs of different load devices.

[0059] In an optional embodiment, the monitoring and protection module includes a temperature monitoring module, an overcurrent protection module, an overvoltage protection module and an undervoltage protection module; the temperature monitoring module is used to perform temperature monitoring, and performs temperature protection when the temperature is higher than a temperature threshold; the overcurrent protection module is used to perform current monitoring, and performs overcurrent protection when the current is higher than a current threshold; the overvoltage protection module is used to perform voltage monitoring, and performs overvoltage protection when the voltage is higher than a first voltage threshold; the undervoltage protection module is used to perform voltage monitoring, and performs undervoltage protection when the voltage is lower than a second voltage threshold.

[0060] Specifically, Figure 7 As shown in the figure, the temperature monitoring module, overcurrent protection module, overvoltage protection module and undervoltage protection module are connected to the microgrid controller signal through the wireless transmission module. Among them, the temperature monitoring module detects the temperature of each module in the system in real time. Since some modules in the system will generate heat during operation, excessive temperature will affect their performance and life, and even cause safety accidents. Therefore, the temperature monitoring module can detect and deal with potential temperature problems in time by detecting temperature data in real time to ensure the stable operation of the system. The overcurrent protection module monitors the current in the system. When the current exceeds the set threshold, the module will quickly start the protection mechanism, cut off the overcurrent path, and prevent the equipment from being damaged due to overcurrent. The existence of the overcurrent protection module can effectively protect the key equipment in the system, such as inverters, switchgear, etc., and avoid safety accidents caused by overcurrent. The overvoltage protection module monitors the voltage in the system. When the voltage exceeds the set threshold, the module will immediately take measures to reduce the system voltage or cut off the relevant circuit to prevent the equipment from being damaged due to overvoltage. The overvoltage protection module is particularly important for protecting sensitive equipment in the system, such as energy storage batteries and precision electronic equipment. The undervoltage protection module is used to detect whether the voltage in the system is lower than the set threshold. When the voltage is too low, the module will activate the corresponding protection mechanism, such as cutting off the low-voltage circuit, starting the backup power supply, etc., to prevent system instability or equipment damage due to undervoltage. The undervoltage protection module is of great significance to ensure the continuous and stable operation of the system.

[0061] In an optional implementation, the monitoring and protection module further includes an alarm module and a positioning module; the positioning module is used to locate the fault using positioning technology; and the alarm module is used to issue an alarm according to the fault location result.

[0062] Specifically, Figure 7 As shown in the figure, the alarm module and the positioning module are connected through the wireless transmission module and the microgrid controller signal. The positioning module detects and locates the status and fault location information of each module in the system in real time. Through the positioning algorithm in the relevant technology, the positioning module can accurately determine the location of the fault, thereby helping the operation and maintenance personnel to quickly locate the problem, reduce the troubleshooting time, and improve the reliability and stability of the system. After the positioning module locates the fault information, the alarm module will immediately start the early warning function. The alarm module can send fault information to the operation and maintenance personnel in a variety of ways (such as sound and light alarms, SMS notifications, email reminders, etc.), reminding them to take timely measures to deal with it. This timely alarm mechanism can ensure that the operation and maintenance personnel respond in time, reduce the impact of the fault on the system, and ensure the normal operation of the system.

[0063] Among them, the fault detection and diagnosis algorithms used in this embodiment include threshold detection, statistical analysis, machine learning, etc., through which the fault status of the equipment can be detected in real time, such as real-time monitoring and pattern recognition of equipment operating status parameters. Specifically, the threshold detection algorithm can be implemented in the following ways:

[0064] If T>T_{max}, an overheat alarm is issued;

[0065] Where T is the real-time temperature and T_{max} is the set maximum temperature threshold.

[0066] In an optional implementation, the optimization module includes: an intelligent integration module, an intelligent operation and maintenance module, an advanced control and protection module, an energy storage enhancement module, a stability enhancement module and a grid-connected optimization module; the intelligent integration module is used to adopt the Internet of Things technology to realize data transmission in the system through the communication module and the communication protocol; the intelligent operation and maintenance module is used for fault prediction and automatic inspection and fault handling; the advanced control and protection module is connected to the monitoring and protection module for fault protection based on the control algorithm and protection technology. The energy storage enhancement module is connected to the energy storage module to obtain new energy storage materials and technologies and the battery management system to optimize the configuration of the energy storage module; the stability enhancement module is used to obtain new power equipment and control algorithms to enhance the stability of the system; the grid-connected optimization module system is used to obtain new power equipment, control strategies and power management strategies to optimize the system grid connection.

[0067] Specifically, Figure 8As shown, the intelligent integration module, intelligent operation and maintenance module, advanced control and protection module, energy storage enhancement module, stability enhancement module and grid-connected optimization module are connected to the microgrid controller signal through the wireless transmission module. The advanced control and protection module is electrically connected to the monitoring and protection module, the energy storage enhancement module is electrically connected to the energy storage module, the stability enhancement module is electrically connected to the energy conversion module, and the grid-connected optimization module is connected to the energy management module signal through the wireless transmission module.

[0068] Among them, the intelligent integration module and the intelligent operation and maintenance module realize signal connection with the microgrid controller through the wireless transmission module to ensure the real-time transmission of information and the rapid execution of instructions. The advanced control and protection module is electrically connected to the monitoring and protection module to monitor the operating status of the system in real time and take corresponding measures to ensure the safety and stability of the system. The energy storage enhancement module is electrically connected to the energy storage module and is responsible for the intelligent management and maintenance of the energy storage equipment. The stability enhancement module is electrically connected to the energy conversion module to monitor the system's voltage, current and other parameters in real time to improve the system stability. The grid-connected optimization module is connected to the energy management module through the wireless transmission module to ensure that the system can be smoothly connected to the grid and operate stably. These optimization modules work together to improve the performance and management efficiency of the photovoltaic storage AC / DC hybrid microgrid system.

[0069] In this embodiment, the intelligent integration module uses the Internet of Things (IoT) technology to achieve communication between different devices and systems through a gateway or a central controller, and uses standard communication protocols such as MQTT, Zigbee, LoRa, etc. to ensure that data between different devices and systems can be transmitted smoothly, realize automatic identification and configuration of devices, realize plug-and-play functions through predefined configuration files or dynamic programming, and integrate advanced monitoring and diagnostic tools to timely discover and solve problems.

[0070] The advanced control and protection module uses advanced control algorithms, such as model predictive control and optimal control, to precisely control the system. It uses related protection technologies, such as fast circuit breakers and intelligent fuses, to ensure that the source of the fault can be quickly cut off when a system fault occurs, and to monitor the operating status of the system in real time. At the same time, the advanced control and protection module can also use sensors and data acquisition technology to collect key data, use cloud computing or edge computing technology to process and analyze data, and realize intelligent decision-making and adaptive control.

[0071] The energy storage enhancement module uses new energy storage materials and technologies, such as solid-state batteries and flow batteries, to improve the performance of the energy storage module. At the same time, it uses advanced battery management systems in related technologies to monitor battery voltage, current, temperature and other parameters in real time to ensure the safe operation of the battery and achieve intelligent scheduling and optimization of the energy storage module. In addition, it can also control charging and discharging according to system requirements and energy prices, and use energy prediction technologies such as weather forecasts and load forecasts to predict energy storage needs in advance and achieve optimal configuration of energy storage modules.

[0072] The stability enhancement module uses high-performance power electronic equipment and advanced control algorithms, such as voltage source converters and reactive power compensators, to improve the voltage and frequency stability of the system, and obtains advanced fault detection and protection technologies, such as fault current limiters and fast protection relays, to ensure that the source of the fault can be quickly isolated when a system fault occurs. It uses simulation and modeling technology to analyze and optimize the system's stability and improve the system's anti-interference ability and robustness.

[0073] The grid-connected optimization module obtains power electronic equipment and control strategies suitable for DC grid connection, such as DC transformers, DC circuit breakers, etc., to achieve two-way communication and energy exchange with the grid, and uses smart grid technology to achieve coordinated operation with the grid, and obtains advanced power management strategies, such as demand-side response, virtual power plants, etc., to achieve energy complementarity and optimized scheduling with the grid.

[0074] The intelligent operation and maintenance module uses the Internet of Things and big data technologies to achieve remote monitoring and status evaluation of equipment, introduces artificial intelligence and machine learning technologies to predict and diagnose equipment failures, implement intelligent early warning and preventive maintenance, and realize automated inspection and fault handling of equipment. It reduces manual intervention through equipment such as robots or drones, and adopts advanced energy management software and platforms to achieve visual management and decision support of the system.

[0075] In this embodiment, the photovoltaic storage AC / DC hybrid microgrid system is an integrated system integrating photovoltaic power generation, energy storage technology, AC / DC power conversion and intelligent management. The system coordinates and manages photovoltaic power generation modules, energy storage modules, energy conversion modules, energy management modules, monitoring and protection modules and load modules through a microgrid controller. Each module and module is connected to the microgrid controller by a wireless transmission module to realize real-time transmission of information and rapid execution of instructions. Through the unified scheduling of the microgrid controller, the system can realize efficient utilization of photovoltaic energy, intelligent charging and discharging management of energy storage equipment and flexible conversion of AC / DC power, and play an efficient coordination function. At the same time, the introduction of the wireless transmission module makes the communication between the modules within the system faster and more stable, improves the response speed and reliability of the system, and can play the advantage of real-time communication. The overall system adopts a modular design, which is convenient for expansion and upgrading according to actual needs, thereby improving the flexibility, adaptability and scalability of the system.

[0076] The system realizes intelligent management of photovoltaic power generation modules, energy storage modules and load modules through energy management modules. The energy management modules include maximum power point tracking control module, SOC limit management control module, hybrid energy storage system energy management control module, etc. It can perform intelligent prediction and optimized scheduling based on real-time data to ensure efficient use of energy and stable operation of the system. Through intelligent prediction and optimized scheduling, the system can make full use of photovoltaic energy, reduce energy waste and improve energy utilization. The introduction of hybrid energy storage system can provide stable power support in the event of grid load peak or fault, ensure stable operation of the system and enhance system stability. Through intelligent management and optimized scheduling, the system can reduce unnecessary energy consumption and equipment wear, thereby reducing operating costs.

[0077] The monitoring and protection module can monitor the operating status and parameters of each device in the microgrid system in real time, and take protective measures when a fault or abnormal situation occurs. The module includes a temperature monitoring module, an overcurrent protection module, an overvoltage protection module, an undervoltage protection module, etc., which can ensure the safe and stable operation of the system. Through real-time monitoring and fault protection, the system can promptly discover and deal with potential safety hazards, ensure the safe and stable operation of the system, and improve safety. The fault location and alarm function can quickly locate the fault location and issue an alarm, reduce the impact and loss of the fault on the system, and facilitate maintenance. In addition, the real-time monitoring and fault recording functions can facilitate the maintenance of the system, reduce maintenance costs and time, and reduce fault losses.

[0078] The intelligent integration module can solve the technical compatibility and interface matching problems in the system integration process. This module can be responsible for the communication and protocol conversion between different devices and systems to ensure that information can be transmitted smoothly. The intelligent integration module can also realize the automatic configuration and debugging of equipment, reduce manual intervention, and improve integration efficiency. The advanced control and protection module obtains advanced control algorithms and protection strategies to improve the stability and safety of the system. This module can monitor the operating status of the system in real time, respond and handle abnormal situations quickly, prevent the spread of faults and cause greater losses, and can also work with the energy management module to optimize the system operation efficiency. The energy storage enhancement module obtains new energy storage technology to improve the performance of existing energy storage modules, improve energy storage capacity, energy density and service life. This module can realize intelligent management and maintenance of energy storage modules to ensure that they operate in the best state. It can also use energy prediction technology to predict energy storage demand in advance and realize the optimal scheduling of energy storage equipment. The stability enhancement module uses power electronics technology and control strategies to improve the stability of the system. This module can monitor the system's voltage, current and other parameters in real time, respond and handle unstable factors quickly, and can also work with photovoltaic power generation modules and energy storage modules to achieve stable output and storage of energy. The grid-connection optimization module uses technologies and equipment suitable for DC grid connection to improve grid connection efficiency and stability. This module can realize the selection of grid connection points and the formulation of grid connection control strategies to ensure that the system can be smoothly connected to the grid and operate stably. It can also realize two-way interaction with the grid to improve energy utilization efficiency. The intelligent operation and maintenance module uses technologies such as the Internet of Things, big data and artificial intelligence to realize intelligent operation and management. This module can monitor the operating status and performance parameters of the equipment in real time, predict equipment failures and perform maintenance in advance, and can also realize remote control and optimized scheduling of equipment, reduce operation and maintenance costs and improve management efficiency.

[0079] Although the exemplary embodiments and their advantages have been described in detail, those skilled in the art may make various changes, substitutions and modifications to these embodiments without departing from the spirit of the present invention and the scope of protection defined by the appended claims, and such modifications and variations all fall within the scope defined by the appended claims. For other examples, those of ordinary skill in the art should readily understand that the order of the process steps may be changed while maintaining the scope of protection of the present invention.

[0080] In addition, the scope of application of the present invention is not limited to the processes, mechanisms, manufactures, material compositions, means, methods and steps of the specific embodiments described in the specification. From the disclosure of the present invention, it will be easily understood by those skilled in the art that the processes, mechanisms, manufactures, material compositions, means, methods or steps that currently exist or will be developed in the future, which perform substantially the same functions as the corresponding embodiments described in the present invention or obtain substantially the same results, can be applied according to the present invention. Therefore, the claims attached to the present invention are intended to include these processes, mechanisms, manufactures, material compositions, means, methods or steps within their scope of protection.

Claims

1. A photovoltaic energy storage AC / DC hybrid microgrid system, characterized in that: The system includes: a distribution network, a microgrid controller, a wireless transmission module, an optimization module, a photovoltaic power generation module, an energy storage module, an energy conversion module, an energy management module, a monitoring and protection module, and a load module; The distribution network is used to receive external input electric energy for conversion and distribution; The microgrid controller is used to coordinate and control the optimization module, the photovoltaic power generation module, the energy storage module, the energy conversion module, the energy management module and the load module through the wireless transmission module based on the electric energy distributed by the distribution network; The photovoltaic power generation module is used to convert solar energy into electrical energy; The energy storage module is used for storing and releasing electric energy; The energy conversion module is used for conversion between direct current and alternating current; The energy management module is connected to the photovoltaic power generation module, the energy storage module and the energy conversion module, and is used to manage and control the power conversion of the photovoltaic power generation module, the energy storage module and the energy conversion module; The load module is connected to the photovoltaic power generation module, the energy storage module and the energy conversion module, and is used to dispatch the electric energy output by the photovoltaic power generation module, the energy storage module and the energy conversion module according to the load demand; The monitoring and protection module is used to monitor and protect the photovoltaic power generation module, the energy storage module, the energy conversion module and the energy management module; The optimization module is used to optimize the operation of the photovoltaic power generation module, the energy storage module, the energy conversion module, the energy management module, and the monitoring and protection module; The energy management module includes a maximum power point tracking control module, a SOC limit management control module, a hybrid energy storage system energy management control module, a centralized control module, a data monitoring module and an intelligent prediction module; The maximum power point tracking control module is used to adjust the working point of the photovoltaic power generation module; The SOC limit management control module is used to optimize the charging and discharging of the energy storage module according to the energy storage medium; The energy management control module of the hybrid energy storage system includes a battery and a supercapacitor, and is used to realize power distribution between the battery and the supercapacitor according to a first-order low-pass filtering algorithm; The data monitoring module is used to obtain the operating data of the photovoltaic power generation module, the energy storage module and the energy conversion module; The centralized control module is used to perform safety hazard analysis based on the operation data; The intelligent prediction module is used to predict the operation of the energy storage module and optimize the charging and discharging of the energy storage module based on the prediction results; The optimization module includes: an intelligent integration module, an intelligent operation and maintenance module, and an advanced control and protection module; The intelligent integrated module is used to adopt the Internet of Things technology to realize data transmission in the system through communication modules and communication protocols; The intelligent operation and maintenance module is used for fault prediction, automated inspection and fault handling; The advanced control and protection module is connected to the monitoring and protection module and is used for fault protection based on the control algorithm and protection method; The optimization module also includes: an energy storage enhancement module, a stability enhancement module and a grid-connection optimization module; The energy storage enhancement module is connected to the energy storage module and is used to obtain new energy storage materials and methods and the battery management system to optimize the configuration of the energy storage module; The stability enhancement module is used to obtain new power equipment and control algorithms to enhance the stability of the system; The grid-connected optimization module system is used to obtain new power equipment, control strategies and power management strategies to optimize the system grid connection.

2. The photovoltaic-storage AC-DC hybrid microgrid system according to claim 1 is characterized in that: The photovoltaic power generation module includes a photovoltaic panel module, a photovoltaic inverter module, a photovoltaic regulation module and a light intensity sensor module; The photovoltaic panel module is used to convert solar energy into electrical energy; The photovoltaic inverter module is used to convert the electric energy converted by the photovoltaic panel module into alternating current; The light intensity sensor module is used to monitor light intensity; The photovoltaic regulation module is used to regulate the photovoltaic panel module according to the regulation signal generated by the microgrid controller based on the light intensity.

3. The photovoltaic-storage AC-DC hybrid microgrid system according to claim 1 is characterized in that: The energy storage module includes a battery module, a battery management module, a charge and discharge control module and a communication interface module; The battery module is used to store and release electrical energy; The battery management module is used to fine-tune the working state of the battery module according to the working parameters of the battery module; The communication interface module is used to connect to the microgrid controller through the wireless transmission module and receive the control signal of the microgrid controller; The charge and discharge control module is used to control the charge and discharge of the battery module according to the control signals of the microgrid controller, the energy management module and the monitoring and protection module.

4. The photovoltaic-storage-AC-DC hybrid microgrid system according to claim 1 is characterized in that: The load module includes a DC load module, an AC load module and a load controller module; The load controller module is used to generate a load management strategy according to the instructions of the microgrid controller, the external power demand and the priority of the load device; The DC load module is used to schedule the electric energy output by the photovoltaic power generation module, the energy storage module and the energy conversion module according to the load management strategy, and adjust the operating state of the external DC load; The AC load module is used to schedule the electric energy output by the photovoltaic power generation module, the energy storage module and the energy conversion module according to the load management strategy, and adjust the operating state of the external AC load.

5. The photovoltaic-storage AC-DC hybrid microgrid system according to claim 1 is characterized in that: The monitoring and protection modules include temperature monitoring module, overcurrent protection module, overvoltage protection module and undervoltage protection module; The temperature monitoring module is used to monitor the temperature and perform temperature protection when the temperature is higher than the temperature threshold; The overcurrent protection module is used to monitor the current and perform overcurrent protection when the current is higher than the current threshold; The overvoltage protection module is used to monitor the voltage and perform overvoltage protection when the voltage is higher than a first voltage threshold; The undervoltage protection module is used to monitor the voltage and perform undervoltage protection when the voltage is lower than a second voltage threshold.

6. The photovoltaic-storage-AC-DC hybrid microgrid system according to claim 5 is characterized in that: The monitoring and protection module also includes an alarm module and a positioning module; The positioning module is used to locate the fault using positioning technology; The alarm module is used to generate an alarm according to the fault location result.

Images