Light storage integrated system for large ground photovoltaic power station

Abstract

The invention relates to the technical field of light storage fusion power generation, in particular to a light storage integrated system for a large ground photovoltaic power station. The system comprises a photovoltaic module, an energy storage battery system, a light storage converter system and an energy control system, wherein the light storage conversion system is used for receiving a control instruction input by the energy control system, controlling the energy storage battery system to charge and discharge according to the power corresponding to the control instruction, and coupling first electric energy corresponding to the energy storage battery system with second electric energy corresponding to the photovoltaic module at a direct current bus; the coupled direct current is inverted into alternating current to be input into an alternating current power grid; wherein the battery capacity of the energy storage battery system is determined by the photovoltaic power of the photovoltaic module, the power of the light storage conversion system is not less than a preset power threshold value, and the voltage of the direct current bus is not less than a preset voltage threshold value. By adopting the scheme, the power and voltage level of the optical storage integrated system can be improved, so that the application to a large-scale ground photovoltaic power station is realized.

Description

Technical Field

[0001] The present disclosure relates to the technical field of integrated photovoltaic and energy storage power generation, and particularly to an integrated photovoltaic and energy storage system for large-scale ground photovoltaic power stations. Background Art

[0002] Current photovoltaic energy storage coupling is usually carried out on the AC grid connection side, resulting in problems such as the mutual independence of photovoltaic and energy storage systems, difficult scheduling coordination, and unclear economic models, causing low energy storage utilization rate, high photovoltaic curtailment ratio, and poor system regulation ability, which affect the overall benefits of photovoltaic and energy storage power stations. Among them, the mutual independence is mainly reflected in two aspects: one is that the interfaces of photovoltaic and energy storage devices are mutually independent, and the functions of large-capacity photovoltaic inverters and energy storage converters are relatively fixed, and direct integration of the two cannot be achieved; the other is that the control of photovoltaic power stations and energy storage power stations is mutually independent, and their automatic generation control (AGC) scheduling systems and control strategies are designed separately, and scheduling coordination is difficult, and the advantages of integrated photovoltaic and energy storage are not fully utilized. According to statistics, the average utilization rate of new energy energy storage is only 31%, and the combined application of photovoltaic and energy storage has become the main development trend.

[0003] However, at the present stage, the research and application of integrated photovoltaic and energy storage mainly remain in distributed microgrids, industrial and commercial, and household scenarios. For large-scale ground photovoltaic power stations, the research and equipment of integrated photovoltaic and energy storage are not yet mature. For example, the power rating of existing integrated photovoltaic and energy storage units is below 100kW, and the voltage rating is below 1000V, which cannot meet the power (the power of a single photovoltaic string is usually above 200kW) and voltage (above 1000V) requirements of current or future large-scale ground photovoltaic power stations. Summary of the Invention

[0004] The present disclosure aims to solve at least one of the technical problems in the related art to some extent.

[0005] To this end, the purpose of the present disclosure is to propose an integrated photovoltaic and energy storage system for large-scale ground photovoltaic power stations to improve the power and voltage ratings of the integrated photovoltaic and energy storage system, so as to realize the application in large-scale ground photovoltaic power stations.

[0006] To achieve the above object, an embodiment of one aspect of the present disclosure provides an integrated photovoltaic and energy storage system for large-scale ground photovoltaic power stations, including: photovoltaic modules, energy storage battery systems, integrated photovoltaic and energy storage conversion systems, and energy control systems; wherein,

[0007] The photovoltaic-storage inverter system is used to receive the control instructions input by the energy control system, control the charge and discharge of the energy storage battery system according to the power corresponding to the control instructions, couple the first electric energy corresponding to the energy storage battery system and the second electric energy corresponding to the photovoltaic module at the DC bus, and invert the coupled direct current into alternating current and input it into the AC grid;

[0008] Among them, the battery capacity of the energy storage battery system is determined by the photovoltaic power of the photovoltaic module, the power of the photovoltaic-storage inverter system is not less than the preset power threshold, and the voltage of the DC bus is not less than the preset voltage threshold.

[0009] Optionally, the energy control system is used to:

[0010] When receiving the station control dispatching instruction, determine the control instruction according to the dispatching information indicated by the station control dispatching instruction, the first real-time status information of the photovoltaic module, and the second real-time status information of the energy storage battery system;

[0011] When not receiving the station control dispatching instruction, determine the control instruction according to the first real-time status information, the second real-time status information, and the AC output power information of the alternating current.

[0012] Optionally, when the energy control system is further used to determine the control instruction according to the first real-time status information, the second real-time status information, and the AC output power information of the alternating current, it is further used to:

[0013] Determine the influencing factors of the AC output power, and adjust the AC output power indicated by the AC output power information according to the influencing factors of the AC output power, where the influencing factors of the AC output power include at least one of the photovoltaic historical power generation curve and the time-of-use electricity price.

[0014] Optionally, when the energy control system is used to determine the control instruction according to the dispatching information indicated by the station control dispatching instruction, the first real-time status information of the photovoltaic module, and the second real-time status information of the energy storage battery system, specifically:

[0015] Determine the dispatching power in the dispatching information indicated by the station control dispatching instruction, the photovoltaic output power in the first real-time status information of the photovoltaic module, and determine the first power difference between the dispatching power and the photovoltaic output power;

[0016] Determine the maximum output power of the energy storage battery system according to the second real-time status information of the energy storage battery system;

[0017] When the first power difference is greater than zero and less than the maximum output power, determine that the control instruction indicates that the energy storage battery system discharges at the power corresponding to the first power difference;

[0018] When the first power difference is greater than zero and greater than the maximum output power, determine that the control instruction indicates that the energy storage battery system discharges at the maximum output power;

[0019] When the first power difference is less than zero and the absolute value of the first power difference is less than the maximum output power, determine that the control instruction indicates that the photovoltaic module charges the energy storage battery system at the power corresponding to the absolute value of the first power difference;

[0020] When the first power difference is less than zero and the absolute value of the first power difference is greater than the maximum output power, determine that the control instruction indicates that the photovoltaic module charges the energy storage battery system at the maximum output power.

[0021] Optionally, when the energy control system is used to determine the control instruction according to the first real-time status information, the second real-time status information, and the AC output power information of the alternating current, it is specifically used for:

[0022] Determine the AC output power corresponding to the AC output power information, the photovoltaic output power in the first real-time status information of the photovoltaic module, and determine the second power difference between the AC output power and the photovoltaic output power;

[0023] According to the second real-time status information of the energy storage battery system, determine the maximum output power of the energy storage battery system;

[0024] When the second power difference is greater than zero and less than the maximum output power, determine that the control instruction indicates that the energy storage battery system discharges at the power corresponding to the second power difference;

[0025] When the second power difference is greater than zero and greater than the maximum output power, determine that the control instruction indicates that the energy storage battery system discharges at the maximum output power;

[0026] When the second power difference is less than zero and the absolute value of the second power difference is less than the maximum output power, determine that the control instruction indicates that the photovoltaic module charges the energy storage battery system at the power corresponding to the absolute value of the second power difference;

[0027] When the second power difference is less than zero and the absolute value of the second power difference is greater than the maximum output power, determine that the control instruction instructs the photovoltaic module to charge the energy storage battery system at the power of the maximum output power.

[0028] Optionally, the photovoltaic energy storage current conversion system includes a photovoltaic energy storage inverter and a DC conversion unit, and the photovoltaic energy storage inverter includes a photovoltaic controller and a grid-connected inverter unit; or, the photovoltaic energy storage current conversion system includes a photovoltaic energy storage inverter, and the photovoltaic energy storage inverter includes a photovoltaic controller, a DC conversion unit, and a grid-connected inverter unit; where

[0029] The first end of the photovoltaic controller is connected to the photovoltaic module, the first end of the DC conversion unit is connected to the energy storage battery system, the second end of the photovoltaic controller and the second end of the DC conversion unit are coupled on the DC bus, the first end of the grid-connected inverter unit is connected to the DC bus, and the second end of the grid-connected inverter unit is connected to the AC power grid.

[0030] Optionally, the energy storage battery system includes at least one battery pack, and the battery pack is composed of a plurality of energy storage batteries connected in series.

[0031] Optionally, the battery pack is a submerged battery pack, and a liquid circulation pipeline is integrated in the submerged battery pack, and the liquid circulation pipeline is used to realize the injection and evacuation of the submerged coolant.

[0032] Optionally, the battery pack includes a bottom liquid-cooled bottom plate, a lower box body, and an upper cover.

[0033] Optionally, the system further includes:

[0034] A fire protection module, which is used to monitor the energy storage battery system, and when the monitoring result meets the early warning requirements, issue an alarm message and perform fire protection treatment on the energy storage battery system.

[0035] Optionally, the fire protection module and the energy storage battery system are integrated in a cabinet.

[0036] Optionally, the fire protection module includes at least one device among a Pack-level automatic fire extinguishing device, a cluster-level automatic fire extinguishing device, a cluster-level smoke detector, a cluster-level temperature detector, a cluster-level gas detector, and a cluster-level sound and light alarm.

[0037] Optionally, the Pack-level automatic fire extinguishing device is a heat-triggered fire extinguishing device containing a temperature sensing wire, which is used to monitor the ambient temperature of the energy storage battery system and start when the monitored temperature value is greater than the temperature threshold, so as to play a role in primary warning of the energy storage battery system.

[0038] In summary, for the integrated solar and energy storage system for large-scale ground photovoltaic power stations provided by the present disclosure, by directly connecting energy storage to the DC side of the photovoltaic system, the integrated solar and energy storage inverter system can couple the first electric energy corresponding to the energy storage battery system and the second electric energy corresponding to the photovoltaic modules at the DC bus, and invert them into alternating current, which can meet the requirements of the photovoltaic power station and achieve the equipment integration of photovoltaic and energy storage at the DC side; moreover, by using the energy control system to control the integrated solar and energy storage inverter system, the control integration and energy integration of photovoltaic and energy storage are realized, the function of the energy storage as an internal regulator of the photovoltaic can be efficiently realized, the photovoltaic power generation can be stabilized, the power generation amount can be increased, the power and voltage levels of the integrated solar and energy storage system can be improved, thereby realizing the application in large-scale ground photovoltaic power stations.

[0039] Additional aspects and advantages of the present disclosure will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The above and / or additional aspects and advantages of the present disclosure will become apparent and be readily understood from the following description of the embodiments in conjunction with the accompanying drawings, where:

[0041] Figure 1 is a schematic structural diagram of the integrated solar and energy storage system for large-scale ground photovoltaic power stations provided by the embodiments of the present disclosure;

[0042] Figure 2 is a schematic structural diagram of a battery pack provided by the embodiments of the present disclosure;

[0043] Figure 3 is a schematic structural diagram of the hardware of a controller host provided by the embodiments of the present disclosure;

[0044] Figure 4 is a schematic integrated solar and energy storage connection topology diagram of a large-scale ground photovoltaic power station provided by the embodiments of the present disclosure;

[0045] Figure 5 is a curve comparison diagram of the AC-side output power on a certain day provided by the embodiments of the present disclosure;

[0046] Figure 6 is a curve comparison diagram of the AC-side output power on another day provided by the embodiments of the present disclosure;

[0047] Figure 7 is a schematic structural diagram of an integrated solar and energy storage system for large-scale ground photovoltaic power stations provided by the embodiments of the present disclosure;

[0048] Figure 8 is a schematic structural diagram of another integrated solar and energy storage system for large-scale ground photovoltaic power stations provided by the embodiments of the present disclosure;

[0049] Figure 9 Schematic diagram of the structure of an outdoor cabinet provided by an embodiment of the present disclosure. Detailed implementation manners

[0050] Embodiments of the present disclosure will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present disclosure, and should not be construed as a limitation to the present disclosure.

[0051] The present disclosure will be described in detail below in conjunction with specific embodiments.

[0052] Figure 1 Schematic diagram of the structure of an integrated energy storage and photovoltaic system for a large-scale ground photovoltaic power station provided by an embodiment of the present disclosure. As Figure 1 shown, the integrated energy storage and photovoltaic system for a large-scale ground photovoltaic power station includes: photovoltaic modules, an energy storage battery system, an energy storage and conversion system, and an energy control system; wherein,

[0053] The energy storage and conversion system is configured to receive a control instruction input by the energy control system, control the energy storage battery system to charge and discharge according to the power corresponding to the control instruction, couple the first electric energy corresponding to the energy storage battery system and the second electric energy corresponding to the photovoltaic modules at the DC bus, and invert the coupled direct current into alternating current and input it to the AC grid.

[0054] According to some embodiments, the photovoltaic modules can serve as the power generation unit of a large-scale ground photovoltaic power station. The photovoltaic modules can be formed by encapsulating a plurality of photovoltaic cells in series or in parallel.

[0055] In some embodiments, the energy storage battery system can serve as an internal regulator for the power generation of the photovoltaic modules, can store the excess power generated by the photovoltaic modules, and can also supplement the power when the power generation of the photovoltaic modules is insufficient.

[0056] According to some embodiments, the battery capacity of the energy storage battery system is determined by the photovoltaic power of the photovoltaic modules. For example, the battery capacity of the energy storage battery system can be configured according to a specific ratio of the photovoltaic power. For example, the power of the energy storage battery system can be configured according to 10-50% of the power of the photovoltaic modules, and the duration can be configured according to 2-6 h.

[0057] In some embodiments, the power of the energy storage and conversion system is not less than a preset power threshold, and the preset power threshold refers to the minimum power value that satisfies a large-scale ground photovoltaic power station. The preset power threshold can be, for example, 200 kW.

[0058] In some embodiments, the voltage of the DC bus is not less than a preset voltage threshold, which can be, for example, 1000V, and the voltage at the DC bus can be, for example, 1400 - 1500V.

[0059] It should be noted that by directly connecting energy storage to the photovoltaic DC side, the photovoltaic energy storage converter system can couple the first electric energy corresponding to the energy storage battery system and the second electric energy corresponding to the photovoltaic modules at the DC bus, and invert it into alternating current, which can meet the requirements of the photovoltaic power station and realize the equipment integration of photovoltaic and energy storage at the DC side; moreover, by using an energy control system to control the photovoltaic energy storage converter system, the control integration and energy integration of photovoltaic and energy storage can be realized, the function of the energy storage as an internal regulator of the photovoltaic can be efficiently realized, the photovoltaic power generation can be stabilized, the power generation can be increased, the power and voltage levels of the photovoltaic energy storage integrated system can be improved, so as to realize the application in large-scale ground photovoltaic power stations.

[0060] Optionally, the energy storage battery system includes at least one battery pack, and the battery pack is composed of a plurality of energy storage batteries connected in series.

[0061] According to some embodiments, the battery type of the energy storage battery includes but is not limited to lithium-ion batteries, sodium-ion batteries, etc. The energy storage battery can be, for example, a battery module.

[0062] In some embodiments, the number of energy storage batteries is determined by the battery capacity of the energy storage battery system.

[0063] In some embodiments, when there are multiple battery packs in the energy storage battery system, the multiple battery packs can be connected in series into a battery cluster according to the capacity requirements.

[0064] According to some embodiments, the battery pack can adopt an immersion-type battery pack, and a liquid circulation pipeline is integrated in the immersion-type battery pack, and the liquid circulation pipeline is used to realize the injection and evacuation of the immersion-type coolant.

[0065] In some embodiments, the materials in the immersion-type coolant include but are not limited to transformer oil, fluorinated liquid, etc.

[0066] Taking a scenario as an example, the battery part configuration in the energy storage battery system can be 1P312S, the battery type is a lithium iron phosphate 280Ah battery, which is composed of 6 immersion-type battery packs (1P52S), and each immersion-type battery pack is composed of 4 battery modules of 1P13S. The power of the energy storage battery system is 279.552kWh, and the voltage range is 780 - 1138V.

[0067] According to some embodiments, the battery pack can also include a bottom liquid-cooled bottom plate, a lower box body, and an upper cover.

[0068] For example, Figure 2 is a schematic structural diagram of a battery pack provided by an embodiment of the present disclosure. AsFigure 2 As shown, the battery pack can be based on the bottom plate for cooling the battery pack housing. The lower box body is made of an aluminum box, and the upper cover is made of sheet metal to ensure the strength and sealing performance of the battery pack housing.

[0069] In some embodiments, when both the liquid circulation pipeline and the bottom liquid cooling plate are used, when the immersion coolant is injected, the battery thermal management method of the energy storage battery system can adopt the parallel method of bottom liquid cooling plate cooling and full - range immersion liquid cooling to effectively improve the temperature uniformity of the battery; when the immersion coolant is not injected, only the bottom liquid cooling plate cooling is retained.

[0070] Among them, when adopting the parallel method of bottom liquid cooling plate cooling and full - range immersion liquid cooling, transformer oil and two water pumps can be injected into the immersion battery pack.

[0071] According to some embodiments, explosion - proof valves, exhaust valves and other devices can also be equipped inside the battery pack, and special compartments can also be set inside the battery pack housing to place devices such as the Battery Management System (BMS) and acquisition lines.

[0072] In some embodiments, the battery management system can monitor the data related to battery heat and electricity in the energy storage battery system in real time and can perform information interaction with the photovoltaic - storage inverter system and the energy control system.

[0073] Taking a scenario as an example, for a single battery module, 5 temperature acquisition points can be arranged on the top cover of the battery cell, and 8 temperature acquisition points can be arranged on the side for the battery management system to collect relevant data.

[0074] Optionally, the photovoltaic - storage inverter system includes a photovoltaic - storage inverter and a DC conversion unit. The photovoltaic - storage inverter includes a photovoltaic controller and a grid - connected inverter unit; or, the photovoltaic - storage inverter system includes a photovoltaic - storage inverter, and the photovoltaic - storage inverter includes a photovoltaic controller, a DC conversion unit and a grid - connected inverter unit; among them,

[0075] The first end of the photovoltaic controller is connected to the photovoltaic module, the first end of the DC conversion unit is connected to the energy storage battery system, the second end of the photovoltaic controller and the second end of the DC conversion unit are coupled on the DC bus, the first end of the grid - connected inverter unit is connected to the DC bus, and the second end of the grid - connected inverter unit is connected to the AC power grid.

[0076] According to some embodiments, the photovoltaic controller is used to control the power of the second electric energy output by the photovoltaic module. This photovoltaic controller can adopt, for example, a photovoltaic maximum power point tracking solar controller (MaximumPower PointTracking, MPPT). The rated power of this photovoltaic controller can be 300kW.

[0077] In some embodiments, the DC conversion unit refers to an energy storage direct current - direct current (DC - DC) unit, which is used to step up or step down the first electric energy corresponding to the energy storage battery system, so as to facilitate subsequent coupling with the second electric energy output by the photovoltaic module. For example, the DC conversion unit can step up the first electric energy output by the energy storage battery system and step down the electric energy input from the photovoltaic module to the energy storage battery system. The rated power of the DC conversion unit can be 60 kW, for example.

[0078] In some embodiments, the grid - connected inverter unit refers to a direct current - alternating current (DC / AC) inverter unit, which is used to invert the coupled direct current into alternating current and input it into the alternating current grid. The rated power of the grid - connected inverter unit can be 240 kW.

[0079] It should be noted that when the photovoltaic - energy storage inverter and the DC conversion unit are independent of each other, the second terminal of the DC conversion unit is connected to the DC bus inside the photovoltaic - energy storage inverter to complete the coupling of the output of the photovoltaic controller and the DC conversion unit on the 1400 - 1500V DC bus. Then, the two share the grid - connected inverter unit in the photovoltaic - energy storage inverter for the conversion from direct current to alternating current; when the DC conversion unit is integrated into the photovoltaic - energy storage inverter, that is, when the photovoltaic controller, the DC conversion unit, and the grid - connected inverter unit are integrated in the photovoltaic - energy storage inverter, the coupling of the DC bus can be completed inside the photovoltaic - energy storage inverter, and the conversion from direct current to alternating current is carried out through the grid - connected inverter unit. These three can share the mechanical structure and control device, which can improve the flexibility and convenience of using the photovoltaic - energy storage current conversion system.

[0080] Optionally, the energy control system can be composed of a controller hardware and a software algorithm part, and the software algorithm part can run on the controller hardware. This energy control system can also be called an energy controller.

[0081] According to some embodiments, the controller hardware includes but is not limited to devices such as a controller host hardware and a display.

[0082] In some embodiments, Figure 3 is a schematic structural diagram of a controller host hardware provided by an embodiment of the present disclosure. As Figure 3As shown, the controller host hardware is equipped with interfaces such as a Local Area Network (LAN) interface, a Controller Area Network (CAN) interface, an RS485 interface, an input interface, an output interface, a Universal Serial Bus (USB) interface, and a High Definition Multimedia Interface (HDMI) interface.

[0083] According to some embodiments, the software algorithm can have functions such as real-time data acquisition, local display function, energy management function protection function, data recording function, etc., and support protocols such as modbus-rtu, modbus-tcp, CAN protocol, etc.

[0084] In some embodiments, based on the software algorithm, the energy control system can be used for:

[0085] When receiving a substation control dispatch instruction, according to the dispatch information indicated by the substation control dispatch instruction, the first real-time status information of the photovoltaic modules, and the second real-time status information of the energy storage battery system, determine a control instruction;

[0086] When not receiving a substation control dispatch instruction, according to the first real-time status information, the second real-time status information, and the AC output power information of the alternating current, determine a control instruction.

[0087] According to some embodiments, the substation control dispatch instruction can be obtained by communicating with the substation control dispatch system. The substation control dispatch instruction can include control strategies such as substation control AGC, Automatic Voltage Control (AVC), etc. The substation control dispatch instruction includes the dispatch power.

[0088] In some embodiments, the first real-time status information can be obtained by communicating with the photovoltaic storage inverter in the photovoltaic storage conversion system. The first real-time status information includes the real-time power output by the photovoltaic controller.

[0089] In some embodiments, the second real-time status information can be obtained by communicating with the battery management system in the energy storage battery system. The second real-time status information includes status information such as the battery's real-time State of Charge (SOC).

[0090] In some embodiments, the control instruction can be sent to the DC conversion unit to control the output power or input power of the energy storage battery system.

[0091] According to some embodiments, when receiving a station control scheduling instruction sent by a station control scheduling system, the energy control system calculates the energy storage power based on the first real-time status information of the photovoltaic modules, the second real-time status information of the energy storage battery system, and the station control scheduling instruction, and issues it to the photovoltaic-storage inverter system to control the charging and discharging of the energy storage battery, so as to achieve the functions of suppressing the volatility of photovoltaic power generation, energy transfer, and peak shaving and valley filling.

[0092] In some embodiments, when the energy control system is used to determine a control instruction according to the scheduling information indicated by the station control scheduling instruction, the first real-time status information of the photovoltaic modules, and the second real-time status information of the energy storage battery system, it can be used for:

[0093] Determine the scheduling power P2 in the scheduling information indicated by the station control scheduling instruction and the photovoltaic output power P1 in the first real-time status information of the photovoltaic modules, and determine the first power difference P2 - P1 between the scheduling power and the photovoltaic output power;

[0094] Determine the maximum output power Pr of the energy storage battery system according to the second real-time status information of the energy storage battery system;

[0095] When the first power difference P2 - P1 is greater than zero and less than the maximum output power Pr, determine that the control instruction instructs the energy storage battery system to discharge at the power corresponding to the first power difference P2 - P1;

[0096] When the first power difference P2 - P1 is greater than zero and greater than the maximum output power Pr, determine that the control instruction instructs the energy storage battery system to discharge at the maximum output power Pr;

[0097] When the first power difference P2 - P1 is less than zero and the absolute value of the first power difference |P2 - P1| is less than the maximum output power Pr, determine that the control instruction instructs the photovoltaic modules to charge the energy storage battery system at the power corresponding to the absolute value of the first power difference |P2 - P1|;

[0098] When the first power difference P2 - P1 is less than zero and the absolute value of the first power difference |P2 - P1| is greater than the maximum output power Pr, determine that the control instruction instructs the photovoltaic modules to charge the energy storage battery system at the power of the maximum output power Pr.

[0099] According to some embodiments, when the energy control system is not scheduled by the substation control dispatching instruction, the energy storage power can be calculated only through the first real-time status information and the second real-time status information and sent to the photovoltaic energy storage inverter system, so as to realize the function of adjustable AC output power. That is to say, the influencing factors of the AC output power can be determined, and the AC output power indicated by the AC output power information can be adjusted according to the influencing factors of the AC output power, so as to conduct internal energy distribution for the photovoltaic and energy storage batteries. Among them, the influencing factors of the AC output power include but are not limited to the historical power generation curve of the photovoltaic and time-of-use electricity price, etc.

[0100] In some embodiments, after adjusting the AC output power indicated by the AC output power information according to the influencing factors of the AC output power, the AC output power can be a value that varies with different time periods within a day. Additionally, the influencing factors of the AC output power can also be not considered, and the AC output power can be fixed as a constant value.

[0101] In some embodiments, when the energy control system is used to determine the control instruction according to the first real-time status information, the second real-time status information, and the AC output power information of the alternating current, it can be used for:

[0102] Determine the AC output power P3 corresponding to the AC output power information of the alternating current and the photovoltaic output power P1 in the first real-time status information of the photovoltaic module, and determine the second power difference P3 - P1 between the AC output power and the photovoltaic output power;

[0103] According to the second real-time status information of the energy storage battery system, determine the maximum output power Pr of the energy storage battery system;

[0104] When the second power difference P3 - P1 is greater than zero and less than the maximum output power Pr, determine that the control instruction instructs the energy storage battery system to discharge at the power corresponding to the second power difference P3 - P1;

[0105] When the second power difference P3 - P1 is greater than zero and greater than the maximum output power Pr, determine that the control instruction instructs the energy storage battery system to discharge at the maximum output power Pr;

[0106] When the second power difference P3 - P1 is less than zero and the absolute value of the second power difference |P3 - P1| is less than the maximum output power Pr, determine that the control instruction instructs the photovoltaic module to charge the energy storage battery system at the power corresponding to the absolute value of the second power difference |P3 - P1|;

[0107] When the second power difference P3 - P1 is less than zero and the absolute value of the second power difference |P3 - P1| is greater than the maximum output power Pr, determine that the control instruction instructs the photovoltaic module to charge the energy storage battery system at the power of the maximum output power Pr.

[0108] Optionally, Figure 4 It is an integrated connection topology diagram of a large-scale ground photovoltaic power station provided by an embodiment of the present disclosure. As Figure 4 shown, an integrated photovoltaic and energy storage system including at least one photovoltaic module, a set of energy storage battery systems, a set of photovoltaic and energy storage converters, and an energy control system is operated in a large-scale ground photovoltaic power station. Two adjacent photovoltaic modules on the photovoltaic power station are selected. One group is equipped with an energy storage battery system, a photovoltaic and energy storage converter, and an energy controller to form an integrated photovoltaic and energy storage system; an adjacent group is only configured with a conventional photovoltaic inverter, which serves as a photovoltaic inverter prototype that is not scheduled and not power-limited for a long time, to form a photovoltaic power generation system for comparison.

[0109] Among them, the configuration of the photovoltaic module is: 24 branches, each branch has 32 photovoltaic panels, and the power of each photovoltaic panel is 335W. Therefore, the theoretical power corresponding to one string is 335 * 32 * 24 = 257kW.

[0110] Among them, the energy controller communicates bidirectionally with the station control system to obtain AGC and AVC control strategies, and uploads the status information of the integrated photovoltaic and energy storage system; the energy controller can also communicate with the photovoltaic inverter prototype to obtain the photovoltaic power and status information of the prototype, and communicate with the photovoltaic and energy storage inverter to obtain the photovoltaic power and status information, and unidirectionally receive the energy storage battery status information; through the above information, the real-time power of the energy storage is calculated and sent to the energy storage DC-DC unit to control the charging and discharging of the energy storage battery. At the same time, when not scheduled by the station control AGC and AVC, the two-way flow of energy between the photovoltaic and energy storage inverter and the energy storage DC-DC can be realized by adjusting the AC output power; and, the photovoltaic energy output by the photovoltaic and energy storage converter system flows unidirectionally to the AC power grid through the grid-connected inverter unit, and the energy of the AC power grid does not feedback to the energy storage battery.

[0111] According to some embodiments, based on Figure 4 the large-scale ground photovoltaic power station shown, on the same day, the AC output powers of the conventional photovoltaic inverter and the integrated photovoltaic and energy storage system are collected respectively, and the AC side output power curve data is compared to verify the role of the integrated photovoltaic and energy storage system in suppressing the volatility of photovoltaic power generation, energy transfer, peak shaving and valley filling, etc. On that day, the conventional photovoltaic inverter did not receive the station control dispatch instruction and could generate electricity at the maximum power by itself. The integrated photovoltaic and energy storage system did not accept the station control dispatch instruction, and adjusted the AC output power P3 of the integrated photovoltaic and energy storage system to a fixed value or a value that changes with different time periods within a day, and obtained the approximate real-time power P1 of MPPT through a nearby group of photovoltaic inverter prototypes. By calculating P3 and P1, the internal energy distribution between the photovoltaic and the energy storage battery is realized.

[0112] In some embodiments, Figure 5 It is a curve comparison diagram of the AC side output power on a certain day provided by an embodiment of the present disclosure. AsFigure 5 As shown, it shows the AC output power curve of a conventional PV inverter on the same day and the AC output power curve of a certain day when P3 of the PV-battery integrated system is set to different values. Among them, before 14:50, the energy storage system in the PV-battery integrated system is in the off state. Through curve comparison, it can be seen that the power curves of the PV-battery integrated system and the conventional PV inverter almost coincide, indicating that the lighting conditions of the two are almost the same, and the maximum power on the same day appears at 12:20, which are 166.92 kW and 167.34 kW respectively. At 15:00, the energy storage in the PV-battery integrated system is turned on, and P3 is set to 35 kW. At this time, since the MPPT power > 35 kW, the excess PV starts to charge the energy storage system; at 15:30, P3 is set to 5 kW. Similarly, since the MPPT power > 5 kW, the excess PV continues to charge the energy storage system.

[0113] In some embodiments, Figure 6 This is a curve comparison diagram of the AC-side output power on another day provided by the embodiments of the present disclosure. As Figure 6 shown, it shows the AC output power curve of a conventional PV inverter from 7:00 to 10:05 in the morning on another day and the AC output power curve when P3 of the PV-battery integrated system is set to different values. There is the influence of clouds on this day. From Figure 6 it can be seen that due to partial occlusion by clouds on this day, the power curve of the conventional PV inverter fluctuates. However, since P3 of the PV-battery integrated system is set to 5 kW, 20 kW, 80 kW, and 120 kW at different times respectively, through the charge and discharge of the energy storage battery, a stable power set value is always output, so the curve is a stepped straight line.

[0114] Among them, as Figure 6 shown, at 7:10 in the morning, P3 is set to 5 kW, and the MPPT power is insufficient, and the energy storage battery is discharging; from 7:25 to 8:25, P3 is set to 20 kW. Before 7:54, the MPPT power is insufficient, and the energy storage battery continues to discharge. However, from 7:55 to 8:25, the MPPT power > 20 kW, and the energy storage battery is charging; from 8:26 to 9:06, P3 is set to 80 kW, and the MPPT power is insufficient, and the energy storage battery is discharging; from 9:07 to 10:05, P3 is set to 120 kW, and the MPPT power is insufficient, and the energy storage battery continues to discharge. Since the energy storage supplements the PV power generation, the power generation in this period is increased.

[0115] The above results show that the energy storage of the PV-battery integrated system can be used as an internal regulator of the PV, and according to the issued value of the active power on the AC side, energy is distributed between the PV and the energy storage, which can effectively play the roles in aspects such as energy transfer, suppressing the volatility of PV power generation, and peak shaving and valley filling.

[0116] Optionally, the integrated energy storage and photovoltaic system for large-scale ground photovoltaic power plants further includes:

[0117] A fire protection module for monitoring the energy storage battery system, and when the monitoring result meets the early warning requirements, sending an alarm message and performing fire protection treatment on the energy storage battery system.

[0118] According to some embodiments, the fire protection module and the energy storage battery system can be integrated in one cabinet. Other devices such as an energy control system, a liquid cooling unit, a high-voltage box, a switch, and an emergency stop module can also be integrated in this cabinet.

[0119] In some embodiments, the fire protection module includes at least one of devices such as a Pack-level automatic fire extinguishing device, a cluster-level automatic fire extinguishing device, a cluster-level smoke detector, a cluster-level temperature detector, a cluster-level gas detector, and a cluster-level sound and light alarm.

[0120] Among them, the Pack-level automatic fire extinguishing device is a heat-triggered fire extinguishing device containing a temperature sensing wire, which is used to monitor the ambient temperature of the energy storage battery system and starts when the monitored temperature value is greater than the temperature threshold, playing a role in primary early warning of the energy storage battery system.

[0121] Among them, the heat-triggered fire extinguishing device can be a thermo-aerosol or heat-triggered perfluorohexanone.

[0122] Among them, the materials used in the cluster-level automatic fire extinguishing device include but are not limited to thermo-aerosol, perfluorohexanone, compressed air foam, etc.

[0123] Among them, the liquid cooling unit is used to control the temperature of the energy storage battery system.

[0124] Among them, the high-voltage box is used for electrical connection and distribution, protection and safety control, compact integration and providing interfaces, etc. in the integrated energy storage and photovoltaic system.

[0125] Among them, the switch is used to realize communication between various devices in the integrated energy storage and photovoltaic system.

[0126] Among them, the emergency stop module is used for staff to manually control the integrated energy storage and photovoltaic system to stop working.

[0127] In some embodiments, the cabinet can be the cabinet of an outdoor cabinet. The main material of the cabinet can be carbon structural steel, and an anti-corrosion paint is sprayed. The protection level is above IP55, and it has functions such as anti-corrosion, waterproof, shockproof, ventilation and heat dissipation, and anti-backwind.

[0128] Taking a scenario as an example, Figure 7 is a schematic structural diagram of an integrated energy storage and photovoltaic system for large-scale ground photovoltaic power plants provided by an embodiment of the present disclosure; as Figure 7As shown in the figure, the system includes a photovoltaic module 1, an outdoor cabinet 2, a photovoltaic energy storage inverter 3, and an energy storage DC-DC unit 4. Among them, the photovoltaic energy storage inverter 3 and the energy storage DC-DC unit 4 are independent of each other. Figure 8 It is a schematic structural diagram of another integrated photovoltaic and energy storage system for large-scale ground photovoltaic power stations provided by an embodiment of the present disclosure; as Figure 8 shown in the figure, the system only includes a photovoltaic module 1, an outdoor cabinet 2, and a photovoltaic energy storage inverter 5 with an integrated energy storage DC-DC unit inside. Figure 9 It is a schematic structural diagram of an outdoor cabinet provided by an embodiment of the present disclosure; as Figure 9 shown in the figure, the outdoor cabinet integrates an immersion battery pack, a liquid chiller, a fire protection module (including a smoke detector, a temperature sensor, a gas detector, a perfluoromethylcyclohexane module, etc.), a high-voltage box, an energy controller, a display screen, an emergency stop module, and a switch.

[0129] In summary, the integrated photovoltaic and energy storage system for large-scale ground photovoltaic power stations provided by the embodiments of the present disclosure improves the configuration mode of the existing ground photovoltaic and energy storage systems, realizes the coupling of the ground photovoltaic and energy storage systems on the DC side, achieves equipment integration through the development of the photovoltaic energy storage conversion system, and achieves control integration and energy integration through the development of the energy controller. After being applied to a ground photovoltaic power station, the energy storage can be used as a flexible internal regulator of the photovoltaic to realize the automatic internal distribution of photovoltaic and energy storage. After large-scale application, it can effectively reduce the losses of photovoltaic over-allocation and light curtailment, improve the total power generation of the photovoltaic energy storage power station, improve the controllability of photovoltaic power generation, increase the utilization rate of photovoltaic and energy storage equipment, flexibly dispatch the DC side of the photovoltaic and energy storage, and also improve the power market regulation ability of the photovoltaic and energy storage, and increase the economic benefits of the power station. It is of great significance in the process of large-scale construction and rapid development of photovoltaic and energy storage, and is the main development trend in the future.

[0130] The collection, storage, use, processing, transmission, provision, and disclosure of user personal information involved in the present disclosure all comply with the provisions of relevant laws and regulations and do not violate public order and good customs.

[0131] It should be noted that personal information from users should be collected for legal and reasonable purposes and should not be shared or sold outside of these legal uses. In addition, such collection / sharing should be carried out after obtaining the informed consent of the user, including but not limited to notifying the user to read the user agreement / user notice and sign an agreement / authorization including authorizing relevant user information before the user uses the function. In addition, any necessary steps should be taken to protect and safeguard access to such personal information data and ensure that others with access to personal information data comply with their privacy policies and procedures.

[0132] The present disclosure anticipates providing embodiments in which users can selectively block the use or access of personal information data. That is, the present disclosure anticipates providing hardware and / or software to prevent or block access to such personal information data. Once the personal information data is no longer needed, the risk can be minimized by restricting data collection and deleting the data. In addition, when applicable, personal identifiers are removed from such personal information to protect the privacy of users.

[0133] In the technical solutions of the present disclosure, the acquisition, transmission, storage, use, processing, etc. of data all comply with the relevant provisions of national laws and regulations.

[0134] It should be noted that in the embodiments of the present disclosure, some industry-existing solutions such as certain software, components, models, etc. may be mentioned. They should be regarded as exemplary, and their purpose is only to illustrate the feasibility in the implementation of the technical solutions of this application, but it does not mean that the applicant has already or necessarily used this solution.

[0135] In the descriptions of the foregoing embodiments, the descriptions with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0136] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" can explicitly or implicitly include at least one of such features. In the description of the present disclosure, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0137] Any process or method description shown in a flowchart or described in other ways herein can be understood as representing a module, segment, or part of code including one or more executable instructions for implementing a customized logic function or process. The scope of the preferred embodiments of the present disclosure includes additional implementations, where the functions can be executed in a manner that is not shown or discussed in sequence, including in a substantially simultaneous manner or in a reverse order according to the functions involved, which should be understood by those skilled in the art to which the embodiments of the present disclosure belong.

[0138] The logic and / or steps represented in the flowchart or otherwise described herein can, for example, be considered as a definitional sequence of executable instructions for implementing logical functions, and can be embodied specifically in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by or in connection with the instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection portion having one or more wirings (electronic device), a portable computer diskette (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can even be paper or other suitable medium on which a program can be printed, as the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpretation, or other appropriate processing as necessary, and then stored in a computer memory.

[0139] It should be understood that various parts of the present disclosure can be implemented by hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: a discrete logic circuit having logic gate circuits for implementing logical functions on data signals, an application specific integrated circuit having appropriate combinational logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0140] Those of ordinary skill in the art of the present technology can understand that all or part of the steps carried by the methods of the above embodiments can be completed by instructing relevant hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiments.

[0141] In addition, in various embodiments of the present disclosure, each functional unit may be integrated into a processing module, may exist physically alone for each unit, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. When the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0142] The above-mentioned storage medium may be a read-only memory, a magnetic disk, an optical disc, etc. Although the embodiments of the present disclosure have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present disclosure. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present disclosure.

Claims

1. A photovoltaic storage integrated system for a large-scale ground photovoltaic power station, characterized in that: include: Photovoltaic modules, energy storage battery systems, photovoltaic storage and power conversion systems, energy control systems; among them, The photovoltaic power conversion system is used to receive the control instructions input by the energy control system, control the energy storage battery system to charge and discharge according to the power corresponding to the control instructions, and couple the first electric energy corresponding to the energy storage battery system with the second electric energy corresponding to the photovoltaic module at the DC bus, and invert the coupled DC power into AC power and input it into the AC power grid; Among them, the battery capacity of the energy storage battery system is determined by the photovoltaic power of the photovoltaic module, the power of the photovoltaic storage and power conversion system is not less than a preset power threshold, and the voltage of the DC bus is not less than a preset voltage threshold.

2. The system according to claim 1, characterized in that The energy control system is used for: In the case of receiving a station control dispatch instruction, determining a control instruction according to the dispatch information indicated by the station control dispatch instruction, the first real-time status information of the photovoltaic assembly, and the second real-time status information of the energy storage battery system; In the case where the station control dispatch instruction is not received, the control instruction is determined according to the first real-time status information, the second real-time status information and the AC output power information of the AC power.

3. The system according to claim 2, characterized in that The energy control system is further used to determine the control instruction according to the first real-time status information, the second real-time status information and the AC output power information of the AC power, and is also used to: Determine an AC output power influencing factor, and adjust the AC output power indicated by the AC output power information according to the AC output power influencing factor, wherein the AC output power influencing factor includes at least one of a photovoltaic historical power generation curve and a time-of-use electricity price.

4. The system according to claim 2, characterized in that The energy control system is used to determine the control instruction according to the scheduling information indicated by the station control scheduling instruction, the first real-time status information of the photovoltaic assembly and the second real-time status information of the energy storage battery system, specifically for: Determine the dispatching power in the dispatching information indicated by the station control dispatching instruction, the photovoltaic output power in the first real-time state information of the photovoltaic component, and determine a first power difference between the dispatching power and the photovoltaic output power; Determining the maximum output power of the energy storage battery system according to the second real-time status information of the energy storage battery system; When the first power difference is greater than zero and less than the maximum output power, determining a control instruction to instruct the energy storage battery system to discharge at a power corresponding to the first power difference; When the first power difference is greater than zero and greater than the maximum output power, determining a control instruction to instruct the energy storage battery system to discharge at the maximum output power; When the first power difference is less than zero and the absolute value of the first power difference is less than the maximum output power, determining a control instruction to instruct the photovoltaic component to charge the energy storage battery system with a power corresponding to the absolute value of the first power difference; When the first power difference is less than zero and the absolute value of the first power difference is greater than the maximum output power, a control instruction is determined to instruct the photovoltaic component to charge the energy storage battery system with the maximum output power.

5. The system according to claim 2, characterized in that The energy control system is used to determine the control instruction according to the first real-time status information, the second real-time status information and the AC output power information of the AC power, specifically for: Determine the AC output power corresponding to the AC output power information of the AC power and the photovoltaic output power in the first real-time status information of the photovoltaic component, and determine a second power difference between the AC output power and the photovoltaic output power; Determining the maximum output power of the energy storage battery system according to the second real-time status information of the energy storage battery system; When the second power difference is greater than zero and less than the maximum output power, determining a control instruction to instruct the energy storage battery system to discharge at a power corresponding to the second power difference; When the second power difference is greater than zero and greater than the maximum output power, determining a control instruction to instruct the energy storage battery system to discharge at the maximum output power; When the second power difference is less than zero and the absolute value of the second power difference is less than the maximum output power, determining a control instruction to instruct the photovoltaic component to charge the energy storage battery system with a power corresponding to the absolute value of the second power difference; When the second power difference is less than zero and the absolute value of the second power difference is greater than the maximum output power, a control instruction is determined to instruct the photovoltaic component to charge the energy storage battery system with the maximum output power.

6. The system according to claim 1, characterized in that The photovoltaic storage conversion system includes a photovoltaic storage inverter and a DC conversion unit, wherein the photovoltaic storage inverter includes a photovoltaic controller and a grid-connected inverter unit; or, the photovoltaic storage conversion system includes a photovoltaic storage inverter, wherein the photovoltaic storage inverter includes a photovoltaic controller, a DC conversion unit and a grid-connected inverter unit; wherein, The first end of the photovoltaic controller is connected to the photovoltaic component, the first end of the DC conversion unit is connected to the energy storage battery system, the second end of the photovoltaic controller is coupled to the second end of the DC conversion unit on the DC bus, the first end of the grid-connected inverter unit is connected to the DC bus, and the second end of the grid-connected inverter unit is connected to the AC power grid.

7. The system according to claim 1, characterized in that The energy storage battery system comprises at least one battery pack, wherein the battery pack is composed of a plurality of energy storage batteries connected in series; The battery pack is an immersed battery pack, in which a liquid circulation pipeline is integrated, and the liquid circulation pipeline is used to realize the injection and emptying of immersion cooling liquid.

8. The system according to claim 7, characterized in that The battery pack includes a bottom liquid-cooled base plate, a lower box body and an upper cover.

9. The system according to claim 1, characterized in that The system further comprises: The fire protection module is used to monitor the energy storage battery system, and when the monitoring result meets the early warning requirements, issue an alarm message and perform fire protection on the energy storage battery system.

10. The system according to claim 9, characterized in that The fire protection module includes at least one device selected from the group consisting of a pack-level automatic fire extinguishing device, a cluster-level automatic fire extinguishing device, a cluster-level smoke detector, a cluster-level temperature detector, a cluster-level gas detector, and a cluster-level sound and light alarm; The Pack-level automatic fire extinguishing device is a heat-triggered fire extinguishing device containing a temperature sensing wire, which is used to monitor the ambient temperature of the energy storage battery system and is activated when the monitored temperature value is greater than the temperature threshold, thereby providing a primary warning for the energy storage battery system.

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