A control method and device for a photovoltaic storage flexible direct current system

Abstract

This invention discloses a control method and device for a photovoltaic-storage-flexible DC system, belonging to the technical field of photovoltaic-storage-flexible DC system technology. The method includes: firstly, determining the real-time power value of the grid connection point in the transformer substation and determining the photovoltaic absorption power value, and using the absorption power value as the charging power value of the energy storage device; then, determining the scenario in which the transformer substation is located based on the real-time power value of the grid connection point and the anti-reverse current lower limit value of the energy storage device; finally, determining the energy storage action according to the scenario and the absorption power value, which can adjust the energy storage device in the photovoltaic-storage-flexible DC system in real time according to the scenario, avoiding photovoltaic waste in the photovoltaic-storage-flexible DC system.

Description

Technical Field

[0001] This invention belongs to the technical field of optical-storage-flexible-direction systems, specifically relating to a control method and device for an optical-storage-flexible-direction system. Background Technology

[0002] The photovoltaic-storage-flexible DC system is a DC system that utilizes photovoltaic power generation and energy storage devices to participate in flexible regulation. In existing low-power scenarios, multi-station photovoltaic-storage-flexible DC systems rely on fixed preset values ​​for the planned power of energy storage during peak and valley periods. The regulation and control process is not flexible enough and is prone to wasting the electricity generated by photovoltaics. Low-power scenarios refer to scenarios in interconnected stations where there is a single or multiple interconnected stations with a load rate of 0 and all stations have a small load, but the corresponding station photovoltaics cannot be fully absorbed. Furthermore, in the case of multi-station interconnection, the existing technology causes system-level operational anomalies due to the large amount of data, and relies too much on the accumulation of historical operating data of the stations.

[0003] Therefore, how to reduce photovoltaic waste in photovoltaic-storage-flexible DC systems in low-power scenarios and improve the robustness of photovoltaic-storage-flexible DC systems is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to solve the technical problems of excessive photovoltaic waste and low robustness in photovoltaic-storage-flexible DC systems in low-power scenarios in the prior art.

[0005] To achieve the above technical objectives, on the one hand, the present invention provides a control method for a flexible direct current system based on optical storage in low-power scenarios, the method comprising:

[0006] Determine the real-time power value of the grid connection point in the transformer area, and determine the photovoltaic power consumption value, and use the power consumption value as the charging power value of the energy storage device;

[0007] The scenario in which the transformer area is located is determined based on the real-time power value of the grid connection point and the lower limit value of the energy storage device for preventing backflow.

[0008] The energy storage action is determined based on the scenario and the power consumption value.

[0009] Furthermore, the scenarios specifically include charging scenarios and discharging scenarios, and the step of determining the energy storage action based on the scenarios and the power consumption value specifically includes:

[0010] If the scenario is a charging scenario, the energy storage device is charged by controlling the power absorption value;

[0011] If the scenario is a discharge scenario, then the discharge power of the energy storage device is determined and the energy storage device is controlled to discharge.

[0012] Furthermore, the determination of the scenario in which the distribution area is located based on the real-time power value of the grid connection point and the anti-backflow lower limit value of the energy storage device specifically includes:

[0013] If the real-time power value at the grid connection point is less than the lower limit of the energy storage device's anti-reverse current value, then the scenario is a charging scenario; if the real-time power value is not less than the lower limit of the energy storage device's anti-reverse current value, then the scenario is a discharging scenario.

[0014] Furthermore, the power absorption value is not less than the actual operating power value of the photovoltaic system, and the lower limit value for anti-reverse current in the transformer area is higher than the photovoltaic reverse current value of the corresponding transformer area.

[0015] Furthermore, the method also includes:

[0016] Determine the real-time power value of each grid connection point in the photovoltaic-storage-flexible-DC system and calculate the average real-time power value of the grid connection point;

[0017] If the average real-time power value of the grid connection point is less than the first preset power value, load balancing operation is performed on each transformer area based on the real-time power value of the grid connection point of each transformer area.

[0018] Furthermore, if the average real-time power value at the grid connection point is not less than the first preset power value, then the transformer substations with a lower limit for flex daisy-chain anti-reverse current that is less than the photovoltaic reverse current value are identified, and the lower limit for flex daisy-chain anti-reverse current in the transformer substations to be adjusted is raised to the average real-time power value at the grid connection point.

[0019] Furthermore, the load balancing operation for each transformer area based on the real-time power value of the grid connection point specifically includes:

[0020] The transformer areas to be subjected to load balancing operations are determined based on the lower limit of the flexible radiator's anti-backflow value, the real-time power value at the grid connection point, and the real-time operating power value of the flexible radiator in each transformer area.

[0021] The total reverse current value is determined based on all the transformer areas to be subjected to load balancing operations. The total reverse current value is the sum of the power values ​​delivered by all transformer areas to be subjected to load balancing operations to the remaining transformer areas that are not subjected to load balancing operations.

[0022] The total reverse current value is used to allocate reverse current values ​​to each transformer area that does not perform load balancing operations.

[0023] Furthermore, if the difference between the lower limit of the flex radiator's anti-backflow value and the real-time power value at the grid connection point, plus the real-time operating power value of the flex radiator, is less than 0, then the corresponding transformer area will be designated as the transformer area to be subjected to load balancing operation.

[0024] On the other hand, the present invention also provides a control device for a flexible optical storage and direct current system, the device comprising:

[0025] The first determining module is used to determine the real-time power value of the grid connection point in the transformer area, and to determine the photovoltaic absorption power value, and to use the absorption power value as the charging power value of the energy storage device.

[0026] The second determining module is used to determine the scenario in which the transformer area is located based on the real-time power value of the grid connection point and the anti-backflow lower limit value of the energy storage device.

[0027] The action execution module is used to determine the energy storage action based on the scenario and the power consumption value.

[0028] This invention provides a control method and device for a photovoltaic-storage-flexible DC system in low-power scenarios. Compared with existing technologies, this method first determines the real-time power value of the grid connection point in the distribution area and the photovoltaic absorption power value, and uses the absorption power value as the charging power value of the energy storage device. Then, based on the real-time power value and the anti-reverse current lower limit value of the energy storage device, the scenario in which the distribution area is located is determined. Finally, the energy storage action is determined according to the scenario and the absorption power value. This method can adjust the energy storage device in the photovoltaic-storage-flexible DC system in real time according to the scenario, avoiding photovoltaic waste in the photovoltaic-storage-flexible DC system. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments or prior art of this specification, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 The diagram shown is a schematic flowchart of the control method for the optical storage flexible direct current system provided in the embodiments of this specification;

[0031] Figure 2 The diagram shown is a structural schematic of the control device for the optical storage flexible direct current system provided in the embodiments of this specification. Detailed Implementation

[0032] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0033] Figure 1This is a flowchart illustrating the control method for a flexible photovoltaic (PV) system provided in the embodiments of this specification. Although this specification provides the method operation steps or device structure shown in the following embodiments or figures, based on conventional methods or without creative effort, the method or device may include more or fewer operation steps or module units after partial merging. In steps or structures where there is no necessary causal relationship in logic, the execution order of these steps or the module structure of the device are not limited to the execution order or module structure shown in the embodiments or figures of this specification. When the method or module structure is applied in actual devices, servers, or terminal products, it can be executed sequentially or in parallel according to the method or module structure shown in the embodiments or figures (e.g., in a parallel processor or multi-threaded processing environment, or even in a distributed processing or server cluster implementation environment).

[0034] The optical-storage flexible DC system control method for low-power scenarios provided in the embodiments of this specification can be applied to terminal devices such as client and server devices, for example... Figure 1 As shown, the method specifically includes the following steps:

[0035] Step S101: Determine the real-time power value of the grid connection point in the transformer area, and determine the photovoltaic absorption power value, and use the absorption power value as the charging power value of the energy storage device.

[0036] Specifically, low-power scenarios refer to situations within an internet-connected distribution area where one or more interconnected distribution areas have a load rate of 0 and all distribution areas have low loads, but the corresponding photovoltaic power cannot be fully absorbed. Determining the absorption power value is to ensure that the energy storage device has sufficient power to absorb all photovoltaic power and avoid photovoltaic curtailment. The steps for determining the absorption power value are as follows:

[0037] 1. Take the maximum value between the rated power of the energy storage device and the rated power of the photovoltaic system, and denot it as P_max;

[0038] 2. Take the maximum value between P_max and the actual photovoltaic operating value P_pv_run, that is, P_des_set1=max(P_max,P_pv_run).

[0039] P_des_set1 is the power absorption value. This value must not exceed the rated power of the energy storage device and must always be no less than the actual operating value of the photovoltaic system, ensuring that the energy storage device can handle all the photovoltaic power generation.

[0040] Step S102: Determine the scenario of the transformer area based on the real-time power value of the grid connection point and the lower limit value of the energy storage device for preventing backflow.

[0041] The scenarios specifically include charging scenarios and discharging scenarios. Determining the energy storage action based on the scenarios and the power consumption value specifically includes:

[0042] If the scenario is a charging scenario, the energy storage device is charged by controlling the power absorption value;

[0043] If the scenario is a discharge scenario, then the discharge power of the energy storage device is determined and the energy storage device is controlled to discharge.

[0044] Specifically, the scenario of the power distribution area is determined based on the real-time power value at the grid connection point and the lower limit of the energy storage device's anti-reverse current. This allows for dynamic adjustment of the energy storage charging and discharging direction. If P_pcc_run ≥ P_des_min, meaning the real-time power value at the grid connection point is not less than the lower limit of the energy storage device's anti-reverse current, it indicates that the load on the power distribution area is high and the energy storage device needs to discharge to support the load. The current scenario is a discharging scenario. If P_pcc_run < P_des_min, it indicates that the load on the power distribution area is low and the energy storage device needs to be charged to absorb photovoltaic power. The current scenario is a charging scenario.

[0045] Step S103: Determine the energy storage action based on the scenario and the power consumption value.

[0046] The step of determining the energy storage action based on the scenario and the power absorption value specifically includes:

[0047] If the scenario is a charging scenario, the energy storage device is charged by controlling the power absorption value. The power absorption value is not less than the actual operating power value of the photovoltaic, and the anti-reverse current lower limit value of the transformer area is higher than the photovoltaic reverse current value of the corresponding transformer area.

[0048] If the scenario is a discharge scenario, then the discharge power of the energy storage device is determined and the energy storage device is controlled to discharge.

[0049] Specifically, when the scenario is a charging scenario, energy storage charging is required to absorb photovoltaic power. P_des_set2 is calculated according to the goal of "stimulating photovoltaic absorption" (the energy storage charging power needs to increase the power at the PCC point to close to P_des_min), and P_des_set2 is the power setting value adapted to the load state. When the scenario is a discharging scenario, P_des_set2 is calculated according to the lower limit of the energy storage device's anti-reverse current value and used as the discharging power of the energy storage device.

[0050] It should be noted that:

[0051] Photovoltaic consumption: By using the lower limit constraint of P_des_set1 (≥P_pv_run), it is ensured that the energy storage is always capable of absorbing all the power generation when the photovoltaic is online, especially when P_pcc_run < P_des_min, forced charging is performed to directly consume the photovoltaic power;

[0052] Peak-valley arbitrage: embedding electricity price signals into charging / discharging operations—prioritizing charging during off-peak hours (storing low-priced electricity) and prioritizing discharging during peak hours (replacing high-priced grid electricity), so that the direction of energy storage charging and discharging is adapted to the peak-valley cycle of electricity prices.

[0053] In summary, the entire logic achieves the dual objectives of "prioritizing grid connection and arbitrage collaboration" in low-power scenarios through dynamic adjustments of "first ensuring photovoltaic grid connection (P_des_set1), then adapting to load and electricity price (P_des_set2)".

[0054] In this embodiment of the application, the method further includes:

[0055] Determine the real-time power value of each grid connection point in the photovoltaic-storage-flexible-DC system and calculate the average real-time power value of the grid connection point;

[0056] If the average real-time power value of the grid connection point is less than the first preset power value, load balancing operation is performed on each transformer area based on the real-time power value of the grid connection point of each transformer area.

[0057] If the average real-time power value at the grid connection point is not less than the first preset power value, then the transformer substations with a lower limit for flexible daisy-chain anti-reverse current that is less than the photovoltaic reverse current value are identified, and the lower limit for flexible daisy-chain anti-reverse current in the transformer substations to be adjusted is raised to the average real-time power value at the grid connection point.

[0058] Specifically, as a power transfer device in the interconnected distribution area, the flexible radiator can transfer power from other distribution areas with higher PCC operating power to the reverse current distribution area when the PCC power operating value of the interconnected distribution area is lower than the radiator's anti-reverse current lower limit. It can also adjust the radiator's anti-reverse current lower limit in real time based on the average operating power of the PCCs of all interconnected distribution areas in the photovoltaic-storage-charging-flexible-DC system and the photovoltaic anti-reverse current lower limit. When the PCC power values ​​of each interconnected distribution area are low, the radiator can be used to balance the power at the grid connection points of each distribution area, thereby achieving load balancing and capacity sharing among the interconnected distribution areas.

[0059] The system can calculate the average power value P_pcc_avg of the PCC points in the interconnected distribution area and obtain the photovoltaic reverse current value P_pv_min, which is the lower limit of photovoltaic reverse current prevention. When P_pcc_avg in the interconnected system is less than the reverse current value supplied by the flexible radiator, the minimum value can be taken to reduce the initial power supplied by the flexible radiator and increase the actual power of the distribution area with lower PCC power, thus avoiding reverse current in each distribution area when photovoltaic DC is shared. When P_pcc_avg in the interconnected system is higher than the reverse current value supplied by the flexible radiator and the lower limit of reverse current prevention for the corresponding single distribution area after adjustment, P_fid_min, is less than P_pv_min, then P_fid_min is increased. In low-power scenarios, if the load in the interconnected distribution area is unbalanced, the lower limit of the load can be increased to the average operating power value P_pcc_avg of the PCC points in the interconnected distribution area or the lower limit of photovoltaic reverse current prevention for the corresponding distribution area, P_pv_min, by adjusting P_fid_min. This can maximize the use of interconnection advantages in low-power scenarios and increase the photovoltaic power generation of the distribution area with lower load through load balancing operations.

[0060] The load balancing operation for each transformer area based on the real-time power value of the grid connection point specifically includes:

[0061] The transformer areas to be subjected to load balancing operations are determined based on the lower limit of the flexible radiator's anti-backflow value, the real-time power value at the grid connection point, and the real-time operating power value of the flexible radiator in each transformer area.

[0062] The total reverse current value is determined based on all the transformer areas to be subjected to load balancing operations. The total reverse current value is the sum of the power values ​​delivered by all transformer areas to be subjected to load balancing operations to the remaining transformer areas that are not subjected to load balancing operations.

[0063] The total reverse current value is used to allocate reverse current values ​​to each transformer area that does not perform load balancing operations.

[0064] Specifically, based on the P_fid_min value of each transformer area, which is also the lower limit of the flex camcorder's backflow prevention, it is determined whether the load power in the transformer area other than the flex camcorder is lower than the lower limit of the flex camcorder's backflow prevention in that transformer area. If (P_fid_min-P_pcc_run+P_fid_run) is less than 0, it means that the load power in the transformer area other than the flex camcorder is lower than the adjusted P_fid_min value. Power can be transmitted to other transformer areas through the flex camcorder equipment to improve the operating power of the transformer area's PCC point. Here, P_fid_run is the real-time operating power value of the flex camcorder.

[0065] In addition, before determining the transformer area to be balanced, it is necessary to compare P_fid_min and P_pv_min and take the larger value to ensure that the lower limit of the flexible transformer's anti-reverse current is higher than the lower limit of the photovoltaic anti-reverse current, so as to prioritize the photovoltaic power generation in a single transformer area to support the load of the transformer area.

[0066] By iterating through all interconnected transformer areas using the value of (P_fid_min-P_pcc_run+P_fid_run), and taking the absolute value of the calculation results for all transformer areas with negative (P_fid_min-P_pcc_run+P_fid_run) values, the results are accumulated. These transformer areas are the ones to be subjected to load balancing operations. The accumulated result is the total reverse flow transfer value P_fid_reflu_total of the interconnected transformer areas.

[0067] Specifically, for the flex TV power transfer setting, the algorithm first adjusts the flex TV's backflow prevention lower limit. Then, based on the backflow prevention lower limit, the corresponding demand transfer value and the demanded transfer value are calculated. When multiple transformer areas are interconnected, the transformer areas are traversed and calculated sequentially to obtain the total demand and total demanded value. The comparison between the two is used to further determine each power transfer setting value. More specifically, the number of transformer areas n to be subjected to load balancing operations and the number of transformer areas m not subjected to load balancing operations are determined. Based on the number of transformer areas m not subjected to load balancing operations and the corresponding real-time power value at the grid connection point, the power value transferred to each transformer area not subjected to load balancing operations is determined. Based on the number of transformer areas n to be subjected to load balancing operations and the total backflow transfer value, the power value transferred outward by the transformer areas to be subjected to load balancing operations is determined.

[0068] This method leverages the load balancing capabilities of flexible power distribution platforms (FTDPs) to prioritize local photovoltaic (PV) power supply in low-power scenarios, followed by interconnected PV power supply to support the load of the interconnected PV power supply. Finally, when the load cannot support PV, energy storage devices are used to charge the PV power supply, adhering to a three-tiered principle. This approach balances the load in low-power scenarios, increasing PV power generation without backflow across all distribution areas, achieving peak-valley arbitrage, and ensuring customer profitability. This method is compatible with both shared and non-shared DC-side configurations for PV and energy storage in multi-distribution interconnected systems. Real-time operating power of PV, energy storage, FTDP, and charging piles is calculated based on the PCC point power. In low-power scenarios, the FTDP interconnection and energy storage charging characteristics are utilized to the maximum extent to balance the load of interconnected distribution areas and achieve PV power integration.

[0069] Based on the above-described control method for a low-power optical-storage-flexible DC-DC system, one or more embodiments of this specification also provide a platform or terminal for controlling such a system. This platform or terminal may include devices, software, modules, plug-ins, servers, clients, etc., using the methods described in the embodiments of this specification, combined with necessary hardware implementation. Based on the same innovative concept, the systems in one or more embodiments provided in this specification are as described in the following embodiments. Since the implementation schemes and methods for solving the system problem are similar, the specific system implementation in the embodiments of this specification can refer to the implementation of the aforementioned methods. Repeated descriptions will not be repeated. The terms "unit" or "module" used below can refer to a combination of software and / or hardware that achieves a predetermined function. Although the systems described in the following embodiments are preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0070] Specifically, Figure 2 This is a schematic diagram of the module structure of one embodiment of the control device for the optical storage flexible direct current system provided in this specification, as shown below. Figure 2 As shown, the optical storage flexible direct current system control device provided in this specification includes:

[0071] The first determining module 201 is used to determine the real-time power value of the grid connection point in the transformer area, and to determine the photovoltaic absorption power value, and to use the absorption power value as the charging power value of the energy storage device.

[0072] The second determining module 202 is used to determine the scenario in which the transformer area is located based on the real-time power value of the grid connection point and the anti-backflow lower limit value of the energy storage device.

[0073] Action execution module 203 is used to determine energy storage actions based on the scenario and the power consumption value.

[0074] It should be noted that the system described above may include other implementation methods based on the description of the corresponding method embodiments. The specific implementation methods can be referred to the description of the corresponding method embodiments above, and will not be elaborated here.

[0075] This application also provides an electronic device, including:

[0076] processor;

[0077] Memory used to store the processor's executable instructions;

[0078] The processor is configured to perform the methods provided in the embodiments described above.

[0079] The electronic device provided in this application embodiment stores executable instructions of the processor in a memory. When the processor executes the executable instructions, it can first determine the real-time power value of the grid connection point in the transformer area and the photovoltaic absorption power value, and use the absorption power value as the charging power value of the energy storage device; then, based on the real-time power value of the grid connection point and the anti-reverse current lower limit value of the energy storage device, it determines the scenario in which the transformer area is located; finally, it determines the energy storage action according to the scenario and the absorption power value, and can adjust the energy storage device in the photovoltaic-storage-flexible DC system in real time according to the scenario, so as to avoid photovoltaic waste in the photovoltaic-storage-flexible DC system.

[0080] The foregoing has described specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are possible or may be advantageous.

[0081] The methods or apparatus described in the embodiments provided in this specification can implement business logic through a computer program and record it on a storage medium. The storage medium can be read and executed by a computer to achieve the effects of the solutions described in the embodiments of this specification, such as:

[0082] Determine the real-time power value of the grid connection point in the transformer area, and determine the photovoltaic power consumption value, and use the power consumption value as the charging power value of the energy storage device;

[0083] The scenario in which the transformer area is located is determined based on the real-time power value of the grid connection point and the lower limit value of the energy storage device for preventing backflow.

[0084] The energy storage action is determined based on the scenario and the power consumption value.

[0085] The storage medium can include physical devices for storing information, typically digitizing the information and then storing it using electrical, magnetic, or optical methods. The storage medium can include: devices that store information using electrical energy, such as various types of memory, like RAM and ROM; devices that store information using magnetic energy, such as hard disks, floppy disks, magnetic tapes, magnetic core memory, bubble memory, and USB flash drives; and devices that store information using optical methods, such as CDs or DVDs. Of course, there are other readable storage media, such as quantum memories and graphene memories.

[0086] The embodiments in this specification are not limited to conforming to industry communication standards, standard computer resource data update and data storage rules, or the situations described in one or more embodiments of this specification. Slightly modified implementations based on certain industry standards or custom methods or embodiments can also achieve the same, equivalent, or similar, or predictable, implementation effects as described above. Embodiments that utilize these modified or modified methods for data acquisition, storage, judgment, and processing still fall within the scope of optional implementations of the embodiments in this specification.

[0087] The controller can be implemented in any suitable manner. For example, it can take the form of a microprocessor or processor and a computer-readable medium storing computer-readable program code (e.g., software or firmware) executable by the (micro)processor, logic gates, switches, application-specific integrated circuits (ASICs), programmable logic controllers, and embedded microcontrollers. Examples of controllers include, but are not limited to, the following microcontrollers: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20, and Silicon Labs C8051F320. A memory controller can also be implemented as part of the control logic of the memory. Those skilled in the art will also recognize that, in addition to implementing the controller in purely computer-readable program code form, the same functionality can be achieved by logically programming the method steps to make the controller take the form of logic gates, switches, ASICs, programmable logic controllers, and embedded microcontrollers. Therefore, such a controller can be considered a hardware component, and the means included therein for implementing various functions can also be considered as structures within the hardware component. Alternatively, the means for implementing various functions can be considered as both software modules implementing the method and structures within the hardware component.

[0088] The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or plug-ins may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, indirect coupling or communication connection between devices or units, and may be electrical, mechanical, or other forms.

[0089] These computer program instructions can also be loaded onto a computer or other programmable resource data updating device, causing a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable device for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0090] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, system embodiments are basically similar to method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments. In the description of this specification, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this specification. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0091] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the principles of the invention, and should be understood that the scope of protection of the invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical teachings disclosed in this invention without departing from the spirit of the invention, and these modifications and combinations are still within the scope of protection of this invention.

Claims

1. A control method for a photovoltaic-storage-flexible direct current system, characterized in that, The method includes: Determine the real-time power value of the grid connection point in the transformer area, and determine the photovoltaic power consumption value, and use the power consumption value as the charging power value of the energy storage device; The scenario in which the transformer area is located is determined based on the real-time power value of the grid connection point and the lower limit value of the energy storage device for preventing backflow. The energy storage action is determined based on the scenario and the power consumption value. Specifically, the scenarios include charging and discharging scenarios, and determining the energy storage action based on the scenarios and the power consumption value specifically includes: If the scenario is a charging scenario, the energy storage device is charged by controlling the power absorption value; If the scenario is a discharge scenario, then the discharge power of the energy storage device is determined and the energy storage device is controlled to discharge. Specifically, the scenario of determining the location of the transformer substation based on the real-time power value of the grid connection point and the anti-backflow lower limit value of the energy storage device includes: If the real-time power value at the grid connection point is less than the lower limit of the energy storage device's anti-reverse current value, then the scenario is a charging scenario; if the real-time power value is not less than the lower limit of the energy storage device's anti-reverse current value, then the scenario is a discharging scenario.

2. The control method for the optical storage flexible direct current system as described in claim 1, characterized in that, The power absorption value is not less than the actual operating power value of the photovoltaic system, and the lower limit value for anti-reverse current in the transformer area is higher than the photovoltaic reverse current value of the corresponding transformer area.

3. The control method for the optical storage flexible direct current system as described in claim 1, characterized in that, The method further includes: Determine the real-time power value of each grid connection point in the photovoltaic-storage-flexible-DC system and calculate the average real-time power value of the grid connection point; If the average real-time power value of the grid connection point is less than the first preset power value, load balancing operation is performed on each transformer area based on the real-time power value of the grid connection point of each transformer area.

4. The control method for the optical storage flexible direct current system as described in claim 3, characterized in that, If the average real-time power value at the grid connection point is not less than the first preset power value, then the transformer substations with a lower limit for flexible daisy-chain anti-reverse current that is less than the photovoltaic reverse current value are identified, and the lower limit for flexible daisy-chain anti-reverse current in the transformer substations to be adjusted is raised to the average real-time power value at the grid connection point.

5. The control method for the optical storage flexible direct current system as described in claim 3, characterized in that, The load balancing operation for each transformer area based on the real-time power value of the grid connection point specifically includes: The transformer areas to be subjected to load balancing operations are determined based on the lower limit of the flexible radiator's anti-backflow value, the real-time power value at the grid connection point, and the real-time operating power value of the flexible radiator in each transformer area. The total reverse current value is determined based on all the transformer areas to be subjected to load balancing operations. The total reverse current value is the sum of the power values ​​delivered by all transformer areas to be subjected to load balancing operations to the remaining transformer areas that are not subjected to load balancing operations. The total reverse current value is used to allocate reverse current values ​​to each transformer area that does not perform load balancing operations.

6. The control method for the optical storage flexible direct current system as described in claim 5, characterized in that, If the difference between the flex RT anti-backflow lower limit value and the real-time power value at the grid connection point, plus the real-time operating power value of the flex RT, is less than 0, then the corresponding transformer area will be designated as the transformer area to be subjected to load balancing operation.

7. A control device for a photovoltaic storage flexible direct current system, characterized in that, The device includes: The first determining module is used to determine the real-time power value of the grid connection point in the transformer area, and to determine the photovoltaic absorption power value, and to use the absorption power value as the charging power value of the energy storage device. The second determining module is used to determine the scenario in which the transformer area is located based on the real-time power value of the grid connection point and the anti-backflow lower limit value of the energy storage device. Action execution module, used to determine energy storage actions based on the scenario and the power consumption value; Specifically, the scenarios include charging and discharging scenarios, and determining the energy storage action based on the scenarios and the power consumption value specifically includes: If the scenario is a charging scenario, the energy storage device is charged by controlling the power absorption value; If the scenario is a discharge scenario, then the discharge power of the energy storage device is determined and the energy storage device is controlled to discharge. Specifically, the scenario of determining the location of the transformer substation based on the real-time power value of the grid connection point and the anti-backflow lower limit value of the energy storage device includes: If the real-time power value at the grid connection point is less than the lower limit of the energy storage device's anti-reverse current value, then the scenario is a charging scenario; if the real-time power value is not less than the lower limit of the energy storage device's anti-reverse current value, then the scenario is a discharging scenario.

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