Optical storage grid-connected-off-grid operation method

Abstract

The invention discloses an optical storage grid-connected and off-grid operation method, which relates to the field of optical storage grid-connected and off-grid operation, and comprises a photovoltaic power generation unit, an energy storage unit, an intelligent switching unit, an energy management system (EMS), and grid-connected operation and off-grid operation controlled by the system, the grid-connected operation comprises the following steps: system connection: uniquely connecting a photovoltaic system with a power grid through an intelligent switch to realize second-level automatic grid connection; in the operation mode, the daily operation mode is grid-connected operation, and the energy storage system and the power grid jointly supply power to the load; and the system automatically or manually switches back to the grid-connected mode after detecting that the power grid recovers normal power supply. Through a current type control method, the voltage of the power grid is tracked, the magnitude of the output current is set, stable grid-connected operation is achieved, the islanding effect is avoided, it is ensured that the photovoltaic power generation system is automatically powered off when the power grid is powered off, the power grid safety is protected, and the charging and discharging process of the energy storage system is reasonably scheduled according to the load requirement and the photovoltaic power generation condition; the energy utilization efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic energy storage grid-connected and off-grid operation, and specifically to a photovoltaic energy storage grid-connected and off-grid operation method. Background Art

[0002] With the acceleration of global energy transformation, renewable energy, especially solar photovoltaic power generation, has been widely used. Photovoltaic is the abbreviation of solar photovoltaic power generation system (Solar power system). Photovoltaic is a new power generation system that uses the photovoltaic effect of solar cell semiconductor materials to directly convert solar radiation energy into electrical energy. It has two modes: independent operation and grid-connected operation.

[0003] At the same time, solar photovoltaic power generation systems are classified into two types: centralized, such as large-scale ground photovoltaic power generation systems in the northwest; and distributed (with a boundary of more than 6MW), such as photovoltaic power generation systems on the roofs of industrial and commercial enterprise buildings and photovoltaic power generation systems on the roofs of residential buildings. Photovoltaic storage systems (a combination of photovoltaics and energy storage) have become an important part of the future energy system because they can effectively solve the intermittent problem of photovoltaic power generation. The grid-connected system relies on the power grid and adopts the mode of "self-generation and self-use, surplus power to the grid". It does not operate during power outages; the off-grid system operates independently and is not affected by power outages, relying on "storage while using" or "storage first and then use". The on-grid and off-grid energy storage system combines the characteristics of both. It can be connected to the power grid and can be powered by energy storage devices when the power grid is out.

[0004] The patent with application number 202311522201.3 discloses a mobile energy storage power station that can be operated on-grid and off-grid, and specifically relates to the technical field of mobile energy storage power stations, which includes a mobile energy storage box, both sides of which are rotatably connected to a rotating plate, and an expansion mechanism is installed at the bottom of the rotating plate; and the expansion structure includes a first photovoltaic power generation panel installed at the bottom of the rotating plate, and both ends of the rotating plate are provided with sleeve shaft blocks fixedly connected to the mobile energy storage box. The present invention adopts an expansion mechanism to make the rotating roller rod rotate inside the sleeve shaft block, and when the upper surface of the first photovoltaic power generation panel is parallel to the upper surface of the mobile energy storage box, the driving reduction motor is turned off, and the reduction drive motor is started to drive the driving screw to rotate inside the guide frame plate, and the upper surfaces of the two first photovoltaic power generation panels and the two second photovoltaic power generation panels realize photovoltaic power generation.

[0005] At present, when photovoltaic and energy storage are connected to the grid, an island effect will occur, which will reduce the quality of electricity, damage electrical equipment, and cause safety hazards. The energy reliability of photovoltaic and energy storage off-grid operation is low, and new energy is easily affected by the environment. The power supply reliability is low, and it is difficult to achieve effective control and scheduling of energy within the microgrid. Summary of the invention

[0006] Based on this, the purpose of the present invention is to provide a photovoltaic storage grid-connected-off-grid operation method to solve the problem of reducing power quality, damaging electrical equipment, and causing safety hazards. The energy reliability of photovoltaic storage off-grid operation is low, new energy is easily affected by the environment, the power supply reliability is low, and it is difficult to achieve technical problems such as effective control and scheduling of energy within the microgrid.

[0007] To achieve the above object, the present invention provides the following technical solution: a photovoltaic energy storage grid-connected and off-grid operation method, comprising a photovoltaic power generation unit, an energy storage unit, an intelligent switching unit, an EMS energy management system, and grid-connected operation and off-grid operation controlled by the system, wherein the grid-connected operation includes:

[0008] System connection: The photovoltaic system is connected to the power grid through a smart switch, achieving automatic grid connection in seconds;

[0009] Operation mode: The daily operation mode is grid-connected operation, and the energy storage system and the grid jointly supply power to the load;

[0010] In the event of a power outage or failure in the power grid, the intelligent switch will automatically disconnect the grid and switch to off-grid operation mode to ensure uninterrupted power supply to important loads.

[0011] Switching conditions: The switching action is triggered by a power outage or fault signal from the power grid; the system automatically or manually switches back to the grid-connected mode after detecting that the power grid has resumed normal power supply;

[0012] Switching process: The intelligent switching unit quickly disconnects from the grid, adjusts the output power of the energy storage system to meet load demand, and monitors and optimizes energy scheduling and control strategies in off-grid operation;

[0013] Switching steps: S1 First, the EMS energy management system needs to detect the current state and determine whether the conditions for switching to the off-grid mode are met;

[0014] After S2 confirms that the switch is possible, the EMS energy management system issues a switch command;

[0015] According to the instruction, S3 intelligent switching unit disconnects from the grid and starts the energy storage unit to ensure power supply in off-grid mode;

[0016] The S4EMS energy management system detects the current off-grid operation status and determines whether the conditions for switching to the grid-connected mode are met;

[0017] After S5 confirms that the conditions are met, the EMS energy management system issues a switching instruction;

[0018] According to the instructions, the S6 intelligent switching unit reconnects to the grid and adjusts the working mode of the energy storage unit to achieve grid-connected operation.

[0019] The present invention is further configured such that the AC system to which the system is connected operates at a voltage level of 380V to ensure compatibility and stability with the power grid.

[0020] The present invention is further configured such that the grid-connected operation mode adjusts the input and output electric power of the energy storage system in real time according to demand; discharges during peak hours and charges during valley hours; prioritizes photovoltaic power generation and connects surplus power to the grid; and realizes the functions of demand response and peak shaving and valley filling.

[0021] The present invention is further configured such that the grid-connected operation adopts a current-type control method to track the grid voltage and set the output current size to achieve stable grid-connected operation, and the grid-connected operation ensures that the photovoltaic power generation system is automatically powered off when the grid is out of power to protect the safety of the grid, wherein the grid-connected operation reasonably schedules the charging and discharging process of the energy storage system according to the load demand and photovoltaic power generation conditions to improve energy utilization efficiency.

[0022] The present invention is further configured such that when the off-grid operation occurs, the intelligent switching unit disconnects from the external power grid and relies on the energy storage unit as the main power supply to supply power to the load. The photovoltaic power generation unit generates electricity when there is sufficient sunlight, and the excess electric energy is stored in the energy storage unit; when there is insufficient sunlight, the energy storage unit supplies power.

[0023] The present invention is further configured such that, during off-grid operation, the EMS energy management system reasonably allocates the energy of the solar panels and the battery pack according to the power demand and energy supply of the base station, predicts the output energy of the solar panels and monitors the power status of the battery pack in real time, so as to achieve optimal energy scheduling.

[0024] The present invention is further configured such that the energy storage unit controls the charging process of the battery pack, including charging start and stop voltage control, charging current control, and temperature monitoring and control, so as to maintain the battery pack within an appropriate power range and ensure its safety and life, and the energy storage unit formulates a reasonable discharge start and stop strategy and discharge power control method to meet the power requirements of the base station and protect the safety of the battery pack.

[0025] The present invention is further configured such that the core device for off-grid operation includes a power supply controller that monitors the output energy of the solar panels, the battery charge and temperature, and controls the energy scheduling, charging and discharging processes;

[0026] Base station power management system: monitors the power demand of the base station and provides demand information to the power supply controller.

[0027] The present invention is further configured such that the EMS energy management system monitors the operating status and parameter information of the photovoltaic storage system in real time, analyzes and processes the system operating data, identifies potential problems and optimizes the system.

[0028] The present invention is further configured such that the system optimization includes: energy storage system configuration optimization: scientifically configuring the capacity and type of the energy storage system according to typical scenarios and probability distribution of new energy output to improve system economy and efficiency;

[0029] Energy scheduling algorithm optimization: Machine learning, artificial intelligence and other technologies optimize energy scheduling algorithms to improve energy utilization efficiency and power supply reliability;

[0030] Inverter control strategy optimization: Optimize the control strategies of grid-connected inverters and off-grid inverters to reduce grid problems and improve system operation stability.

[0031] In summary, the present invention mainly has the following beneficial effects: the grid-connected operation method of the present invention adopts a current-type control method to track the grid voltage and set the output current size, thereby achieving stable grid-connected operation, avoiding the generation of an island effect, ensuring that the photovoltaic power generation system automatically powers off when the grid is out of power, protecting the safety of the grid, and reasonably scheduling the charging and discharging process of the energy storage system according to load demand and photovoltaic power generation conditions to improve energy utilization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural schematic diagram of the optical storage device of the present invention;

[0033] Figure 2 It is a schematic diagram of the flow chart of the grid-connected operation of the present invention;

[0034] Figure 3 A schematic flow chart of the grid-connected switching steps of the present invention;

[0035] Figure 4 It is a flow chart of the grid-connected switching mode of the present invention;

[0036] Figure 5 A monitoring schematic diagram of an energy storage unit of the present invention;

[0037] Figure 6 It is a monitoring schematic diagram of off-grid operation of the present invention. DETAILED DESCRIPTION

[0038] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0039] A photovoltaic energy storage grid-connected and off-grid operation method, such as Figure 1-6 As shown, it includes a photovoltaic power generation unit, an energy storage unit, an intelligent switching unit, an EMS energy management system, and grid-connected operation and off-grid operation controlled by the system. The grid-connected operation includes:

[0040] System connection: The photovoltaic system is connected to the power grid through a smart switch, achieving automatic grid connection in seconds;

[0041] Operation mode: The daily operation mode is grid-connected operation, and the energy storage system and the grid jointly supply power to the load;

[0042] In the event of a power outage or failure in the power grid, the intelligent switch will automatically disconnect the grid and switch to off-grid operation mode to ensure uninterrupted power supply to important loads.

[0043] Switching conditions: The switching action is triggered by a power outage or fault signal from the power grid; the system automatically or manually switches back to the grid-connected mode after detecting that the power grid has resumed normal power supply;

[0044] Switching process: The intelligent switching unit quickly disconnects from the grid, adjusts the output power of the energy storage system to meet load demand, and monitors and optimizes energy scheduling and control strategies in off-grid operation;

[0045] Switching steps: S1 First, the EMS energy management system needs to detect the current state and determine whether the conditions for switching to the off-grid mode are met;

[0046] After S2 confirms that the switch is possible, the EMS energy management system issues a switch command;

[0047] According to the instruction, S3 intelligent switching unit disconnects from the grid and starts the energy storage unit to ensure power supply in off-grid mode;

[0048] The S4EMS energy management system detects the current off-grid operation status and determines whether the conditions for switching to the grid-connected mode are met;

[0049] After S5 confirms that the conditions are met, the EMS energy management system issues a switching instruction;

[0050] According to the instructions, the S6 intelligent switching unit reconnects to the grid and adjusts the working mode of the energy storage unit to achieve grid-connected operation.

[0051] The AC system to which the system is connected operates at a 380V voltage level, ensuring compatibility and stability with the power grid.

[0052] The grid-connected operation mode adjusts the input and output electric power of the energy storage system in real time according to demand; discharges during peak hours and charges during off-peak hours; prioritizes photovoltaic power generation and connects the surplus power to the grid; and realizes the functions of demand response and peak shaving and valley filling.

[0053] The grid-connected operation adopts a current-type control method to track the grid voltage and set the output current size to achieve stable grid-connected operation. The grid-connected operation ensures that the photovoltaic power generation system is automatically powered off when the grid is out of power to protect the safety of the grid. The grid-connected operation reasonably dispatches the charging and discharging process of the energy storage system according to the load demand and photovoltaic power generation situation to improve energy utilization efficiency.

[0054] During off-grid operation, the intelligent switching unit disconnects from the external power grid and relies on the energy storage unit as the main power source to supply power to the load. The photovoltaic power generation unit generates power when there is sufficient sunlight, and the excess electric energy is stored in the energy storage unit; when there is insufficient sunlight, the energy storage unit supplies power.

[0055] During off-grid operation, the EMS energy management system reasonably allocates the energy of the solar panels and the battery pack according to the power demand and energy supply of the base station, predicts the output energy of the solar panels and monitors the power status of the battery pack in real time, so as to achieve optimal energy scheduling.

[0056] The energy storage unit controls the charging process of the battery pack, including charging start and stop voltage control, charging current control, and temperature monitoring and control, so as to maintain the battery pack within an appropriate power range and ensure its safety and life. The energy storage unit formulates a reasonable discharge start and stop strategy and discharge power control method to meet the power demand of the base station and protect the safety of the battery pack.

[0057] The core equipment of the off-grid operation includes a power supply controller: monitoring the output energy of the solar panels, the battery power and temperature, and controlling the energy scheduling, charging and discharging processes;

[0058] Base station power management system: monitors the power demand of the base station and provides demand information to the power supply controller.

[0059] The EMS energy management system monitors the operating status and parameter information of the photovoltaic storage system in real time, analyzes and processes the system operation data, identifies potential problems and optimizes the system.

[0060] The system optimization includes: energy storage system configuration optimization: scientifically configure the capacity and type of energy storage system according to the typical scenarios and probability distribution of new energy output to improve the economy and efficiency of the system;

[0061] Energy scheduling algorithm optimization: Machine learning, artificial intelligence and other technologies optimize energy scheduling algorithms to improve energy utilization efficiency and power supply reliability;

[0062] Inverter control strategy optimization: Optimize the control strategies of grid-connected inverters and off-grid inverters to reduce grid problems and improve system operation stability.

[0063] Working principle of the present invention:

[0064] Although an embodiment of the present invention has been shown and described, this specific embodiment is merely an explanation of the present invention and is not a limitation of the invention. The specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. After reading this specification, those skilled in the art may make modifications, substitutions and variations to the embodiments without creative contributions as needed without departing from the principles and purpose of the present invention. However, as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A photovoltaic energy storage grid-connected and off-grid operation method, comprising a photovoltaic power generation unit, an energy storage unit, an intelligent switching unit, an EMS energy management system, and grid-connected operation and off-grid operation controlled by the system, characterized in that: The grid-connected operation includes: System connection: The photovoltaic system is connected to the power grid through a smart switch, achieving automatic grid connection in seconds; Operation mode: The daily operation mode is grid-connected operation, and the energy storage system and the grid jointly supply power to the load; In the event of a power outage or failure in the power grid, the intelligent switch will automatically disconnect the grid and switch to off-grid operation mode to ensure uninterrupted power supply to important loads. Switching conditions: The switching action is triggered by a power outage or fault signal from the power grid; the system automatically or manually switches back to the grid-connected mode after detecting that the power grid has resumed normal power supply; Switching process: The intelligent switching unit quickly disconnects from the grid, adjusts the output power of the energy storage system to meet load demand, and monitors and optimizes energy scheduling and control strategies in off-grid operation; Switching steps: S1 First, the EMS energy management system needs to detect the current state and determine whether the conditions for switching to the off-grid mode are met; After S2 confirms that the switch is possible, the EMS energy management system issues a switch command; According to the instruction, S3 intelligent switching unit disconnects from the grid and starts the energy storage unit to ensure power supply in off-grid mode; The S4EMS energy management system detects the current off-grid operation status and determines whether the conditions for switching to the grid-connected mode are met; After S5 confirms that the conditions are met, the EMS energy management system issues a switching instruction; According to the instructions, the S6 intelligent switching unit reconnects to the grid and adjusts the working mode of the energy storage unit to achieve grid-connected operation.

2. A photovoltaic energy storage grid-connected and off-grid operation method according to claim 1, characterized in that: The AC system to which the system is connected operates at a 380V voltage level, ensuring compatibility and stability with the power grid.

3. The method for grid-connected and off-grid operation of photovoltaic energy storage according to claim 1, characterized in that: The grid-connected operation mode adjusts the input and output power of the energy storage system in real time according to demand; discharges during peak hours and charges during off-peak hours; prioritizes photovoltaic power generation and connects the surplus power to the grid; Realize the functions of demand response and peak shaving.

4. The method for grid-connected and off-grid operation of photovoltaic energy storage according to claim 1, characterized in that: The grid-connected operation adopts a current-type control method to track the grid voltage and set the output current size to achieve stable grid-connected operation. The grid-connected operation ensures that the photovoltaic power generation system is automatically powered off when the grid is out of power to protect the safety of the grid. The grid-connected operation reasonably dispatches the charging and discharging process of the energy storage system according to the load demand and photovoltaic power generation situation to improve energy utilization efficiency.

5. The method for grid-connected and off-grid operation of photovoltaic energy storage according to claim 1, characterized in that: During off-grid operation, the intelligent switching unit disconnects from the external power grid, and relies on the energy storage unit as the main power source to supply power to the load. The photovoltaic power generation unit generates electricity when there is sufficient sunlight, and the excess electricity is stored in the energy storage unit. When there is insufficient light, the energy storage unit provides power.

6. A photovoltaic energy storage grid-connected and off-grid operation method according to claim 5, characterized in that: During off-grid operation, the EMS energy management system reasonably allocates the energy of the solar panels and the battery pack according to the power demand and energy supply of the base station, predicts the output energy of the solar panels and monitors the power status of the battery pack in real time, so as to achieve optimal energy scheduling.

7. The method for grid-connected and off-grid operation of photovoltaic energy storage according to claim 5, characterized in that: The energy storage unit controls the charging process of the battery pack, including charging start and stop voltage control, charging current control, and temperature monitoring and control, so as to maintain the battery pack within an appropriate power range and ensure its safety and life. The energy storage unit formulates a reasonable discharge start and stop strategy and discharge power control method to meet the power demand of the base station and protect the safety of the battery pack.

8. The method for grid-connected and off-grid operation of photovoltaic energy storage according to claim 5, characterized in that: The core equipment of the off-grid operation includes a power supply controller: monitoring the output energy of the solar panels, the battery power and temperature, and controlling the energy scheduling, charging and discharging processes; Base station power management system: monitors the power demand of the base station and provides demand information to the power supply controller.

9. The method for grid-connected and off-grid operation of photovoltaic energy storage according to claim 1, characterized in that: The EMS energy management system monitors the operating status and parameter information of the photovoltaic storage system in real time, analyzes and processes the system operation data, identifies potential problems and optimizes the system.

10. A photovoltaic energy storage grid-connected and off-grid operation method according to claim 9, characterized in that: The system optimization includes: energy storage system configuration optimization: scientifically configure the capacity and type of energy storage system according to the typical scenarios and probability distribution of new energy output to improve the economy and efficiency of the system; Energy scheduling algorithm optimization: Machine learning, artificial intelligence and other technologies optimize energy scheduling algorithms to improve energy utilization efficiency and power supply reliability; Inverter control strategy optimization: Optimize the control strategies of grid-connected inverters and off-grid inverters to reduce grid problems and improve system operation stability.

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