Off-grid optical storage diesel charging micro-grid system, coordination control method and equipment

Abstract

The invention relates to an off-grid light storage diesel charging micro-grid system, a coordination control method and equipment, and the system comprises a photovoltaic unit used for photovoltaic power generation, an energy storage unit used for storing electric quantity, a charging pile unit, a light storage access unit, a diesel generator unit used for diesel power generation, and a communication management machine. The system comprises an energy management system and a dual-power switching unit which is connected with a photovoltaic unit, an energy storage unit, a diesel generator unit and a charging pile unit. The photovoltaic unit, the energy storage unit and the diesel generator unit are respectively connected to the energy management system through the communication management machine. The dual-power-supply automatic switching device is controlled by the energy management system to realize switching between a light storage charging mode and a diesel charging mode. Compared with the prior art, the method has the advantages of enhancing the stability and reliability of the system, optimizing the energy scheduling and management, dynamically adjusting the energy supply and demand balance, reducing the operation cost and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of microgrids, and in particular to an off-grid photovoltaic storage and diesel charging microgrid system, a coordinated control method and equipment. Background Art

[0002] With the development of renewable energy technology and new energy vehicles, photovoltaic power generation, energy storage technology and charging piles are increasingly used in microgrid systems. However, in some cases where there is no public power grid, the application of photovoltaic storage and charging microgrids will be limited, and it also limits the promotion of new energy vehicles in islands, pastoral areas, remote areas and areas with weak power grids.

[0003] Although off-grid solar-storage-charging systems can partially solve the charging problem of new energy vehicles, the intermittent and unpredictable nature of these energy sources poses challenges to the stability and reliability of microgrids.

[0004] After searching, Chinese invention patent publication number CN106099986B discloses an isolated island integrated energy supply and security system, including: a small reactor nuclear power generation equipment as the main power source of the isolated island microgrid; a switch station for connecting the small reactor nuclear power generation equipment to the microgrid; a large-capacity energy storage system and supercapacitors for energy storage; a distributed renewable energy generation system as an auxiliary power source for the isolated island microgrid; a diesel power generation system as an emergency energy source for the isolated island microgrid; and a microgrid integrated control and management center system, which automatically switches to other power generation systems through the microgrid integrated control and management center system when the main power fails. This existing patent has the problem of not disclosing the switching of multiple power generation systems and not involving the detailed technology of coordinated control of the power generation system and the charging system.

[0005] How to achieve coordinated control of photovoltaic, storage and diesel charging microgrids has become a technical problem that needs to be solved. Summary of the invention

[0006] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide an off-grid photovoltaic storage and diesel charging microgrid system, coordinated control method and equipment.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] According to one aspect of the present invention, an off-grid photovoltaic storage diesel charging microgrid system is provided, which includes a photovoltaic unit for photovoltaic power generation, an energy storage unit for storing electricity, a charging pile unit, a photovoltaic storage access unit, a diesel generator unit for diesel power generation, and a communication management machine, characterized in that the system includes an energy management system and a dual power switching unit respectively connected to the photovoltaic unit, the energy storage unit, the diesel generator unit and the charging pile unit;

[0009] The photovoltaic unit, energy storage unit, photovoltaic storage access unit, diesel generator unit and charging pile unit are respectively connected to the energy management system through the communication management machine;

[0010] The photovoltaic unit and the energy storage unit are respectively connected to the dual power switching unit through the photovoltaic storage access unit;

[0011] The dual power automatic switching device realizes switching back and forth between the solar storage charging mode and the diesel charging mode under the control of the energy management system.

[0012] Preferably, the photovoltaic unit comprises a photovoltaic assembly, a first AC / DC module and a first meter connected in sequence;

[0013] The energy storage unit comprises an energy storage battery, a second AC / DC module and a second meter connected in sequence;

[0014] The photovoltaic storage access unit comprises a third meter and a third circuit breaker connected in sequence;

[0015] The diesel generator unit comprises a diesel generator and a fourth meter connected in sequence;

[0016] The charging pile unit comprises a fifth meter, a fifth circuit breaker and a charging pile device which are connected in sequence.

[0017] More preferably, the energy management system obtains data and status of each unit and the dual power automatic switching device in real time through the communication management machine, and then determines whether to switch the operation mode; wherein each unit includes the data and status of the first AC / DC module, the energy storage battery (21), the second AC / DC module, the third circuit breaker, the diesel generator, the dual power automatic switching device and each circuit meter.

[0018] More preferably, the determining whether to switch the operation mode is specifically:

[0019] If the SOC of the energy storage battery is greater than the lower limit SOCmin of the battery capacity, it is judged that photovoltaic and energy storage meet the requirements of the charging pile, and the dual power supply automatic switching device switches to the photovoltaic storage charging circuit, and the energy management system operates in the photovoltaic storage charging mode; otherwise, the dual power supply automatic switching device switches to the diesel charging circuit, and the energy management system operates in the diesel charging mode, and the diesel generator is used as the main power supply to power the charging pile equipment. At the same time, the photovoltaic storage subsystem operates independently, and the photovoltaic storage subsystem includes a photovoltaic unit and an energy storage unit.

[0020] More preferably, a lower limit SOCminL is set for the energy storage battery (21). When the SOC of the energy storage battery is less than SOCminL, the energy management system starts the diesel generator to make it run. When the SOC of the energy storage battery is less than or equal to SOCmin, the photovoltaic storage subsystem stops supplying power, and the dual power automatic switching device switches to the diesel charging mode; otherwise, the mode is not switched.

[0021] According to another aspect of the present invention, a coordinated control method for an off-grid photovoltaic storage diesel charging microgrid system is provided, the method comprising a coordinated control process in a photovoltaic storage charging mode, including:

[0022] Step S11, real-time acquisition of real-time data of each unit of the photovoltaic storage diesel charging microgrid system;

[0023] Step S12, when the photovoltaic power generation power Ppv is less than the charging power Pch of the charging pile, execute step S14; otherwise, determine whether the SOC of the energy storage battery (21) is less than or equal to the upper limit SOCmax of the remaining energy storage power. If yes, execute step S13; otherwise, the photovoltaic unit operates at a reduced power according to Ppv-Pch;

[0024] Step S13, if the photovoltaic power generation power Ppv is less than the sum of the charging power Pch of the charging pile and the rated power Pe of the energy storage, the photovoltaic unit is preferentially supplied to the charging pile, and the energy storage unit is charged according to the difference between the photovoltaic power generation power Ppv and the charging power Pch of the charging pile; if the photovoltaic power generation power Ppv ≥ the sum of the charging power Pch of the charging pile and the rated power of the energy storage, the photovoltaic unit is preferentially supplied to the charging pile, and the energy storage unit is charged according to the rated power Pe of the energy storage, and the remaining photovoltaic power Ppv-Pch-Pe is discarded, that is, the photovoltaic unit is operated at a reduced power according to Ppv-Pch-Pe, and the process returns to step S11;

[0025] Step S14: if the charging pile charging power Pch is less than or equal to the sum of the photovoltaic power generation power Ppv and the energy storage rated power Pe, execute step S15; otherwise, execute step S16;

[0026] Step S15, the photovoltaic unit is preferentially supplied to the charging pile, and the energy storage unit is discharged according to the difference between the charging power Pch of the charging pile and the photovoltaic power generation power Ppv, and the process returns to step S11;

[0027] Step S16, the photovoltaic unit is preferentially supplied to the charging pile, the energy storage unit is discharged according to the rated power Pe, and the remaining charging power Pch-Ppv-Pe is used to reduce the power of the charging pile to achieve dynamic balance in the light storage and charging mode, and then return to step S11.

[0028] Preferably, the method further includes a coordinated control method in a diesel charging mode, comprising:

[0029] Step S21, real-time data of each unit of the photovoltaic storage diesel charging microgrid system is obtained in real time;

[0030] Step S22, judging whether the rated power Pcfe of the diesel generator is greater than the charging power Pch of the charging pile, if so, the output power Pcf of the diesel generator follows the charging power Pch of the charging pile, and returning to step S21; otherwise, executing step S23;

[0031] Step S23, the diesel generator outputs according to the rated power Pcfe, and the difference between the charging power Pch of the charging pile and the rated power Pcfe of the diesel generator is processed by reducing the power of the charging pile, and then returns to step S21.

[0032] More preferably, the method further comprises that in the diesel charging mode, the photovoltaic storage subsystem operates independently specifically as follows:

[0033] When the photovoltaic power generation power Ppv is greater than the energy storage rated power Pe, the energy storage unit is charged according to the Ppv value, otherwise, the energy storage unit is charged according to the Pe value, and the photovoltaic unit reduces power according to Ppv-Pe.

[0034] Preferably, the method further includes a switching process between a light storage and charging mode and a diesel charging mode: in the diesel charging mode, when the photovoltaic power generation power Ppv is greater than the charging power Pch of the charging pile, or the SOC of the energy storage battery (21) is ≥ the upper limit SOCmax of the remaining energy storage power, the dual power automatic switching device sends a control instruction to operate in the light storage and charging mode, exit the diesel charging mode, and shut down the diesel generator;

[0035] In the photovoltaic storage and charging mode, when the SOC of the energy storage battery (21) is less than the SOC lower limit SOCminL, the diesel generator is started to run, and it is determined whether the SOC of the energy storage battery (21) is ≤ the lower limit SOCmin of the remaining energy storage capacity. If so, the photovoltaic storage system stops supplying power, and the dual power automatic switching device switches to the diesel charging mode; otherwise, it remains in the photovoltaic storage and charging mode.

[0036] According to a third aspect of the present invention, there is provided an electronic device, comprising a memory and a processor, wherein a computer program is stored in the memory, and the method described above is implemented when the processor executes the program.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1) The present invention adds a diesel engine generating unit on the basis of the "photovoltaic storage and charging" microgrid, proposes a "photovoltaic storage and diesel charging" microgrid system, and designs a dual power supply switching algorithm between the photovoltaic storage and charging mode and the diesel generation mode to achieve automatic switching of dual power supplies and orderly charging of charging piles, optimize energy scheduling and management, improve energy utilization efficiency, and thus enhance the reliability and stability of the microgrid system.

[0039] 2) The present invention obtains real-time data of each unit of the photovoltaic storage and diesel charging microgrid system in real time, designs a coordinated control algorithm under two power supply modes, stores excess power in the energy storage unit while giving priority to charging piles, and uses photovoltaic power reduction to operate the remaining energy, dynamically adjusts the energy supply and demand balance, reduces energy waste, improves system self-sufficiency, and reduces system volatility.

[0040] 3) The present invention reduces the dependence on traditional diesel generators, reduces operating costs, and improves economy and environmental friendliness while ensuring the reliability and stability of the microgrid system through coordinated control of the two modes. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic diagram of the structure of the enterprise optical storage system in the present invention;

[0042] Figure 2 It is a flow chart of the coordinated control method in the photovoltaic storage and charging mode of the present invention;

[0043] Figure 3 It is a flow chart of the coordinated control method in the diesel charging mode of the present invention;

[0044] Figure 4 It is a schematic diagram of the conversion process between the solar energy storage charging mode and the diesel charging mode in the present invention;

[0045] In the accompanying drawings, 1 is a photovoltaic unit, 2 is an energy storage unit, 3 is a photovoltaic storage access unit, 4 is a diesel generator unit, 5 is a dual power switching unit, 6 is a charging pile unit, 7 is a communication management machine, 8 is an energy management system, 11 is a photovoltaic component, 12 is a first AC / DC module, 13 is a first meter, 21 is an energy storage battery, 22 is a second AC / DC module, 23 is a second meter, 31 is a third meter, 41 is a diesel generator, 42 is a fourth meter, 61 is a fifth meter, S1 is a first circuit breaker, S2 is a second circuit breaker, S3 is a third circuit breaker, S4 is a fourth circuit breaker, and S5 is a fifth circuit breaker. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0047] In order to solve the reliability and stability problems of the "photovoltaic storage and charging" microgrid, the present invention proposes a "photovoltaic storage and diesel charging" microgrid system. The system effectively improves the energy utilization rate and system stability, and effectively improves the utilization efficiency of diesel generators and reduces the operating costs of charging stations through automatic switching of photovoltaic storage and diesel generator dual power sources and orderly charging of charging piles.

[0048] This embodiment relates to an off-grid photovoltaic storage and diesel charging microgrid system. Figure 1The system includes a photovoltaic unit 1, an energy storage unit 2, a photovoltaic storage access unit 3, a diesel generator unit 4, a dual power switching unit 5, a charging pile unit 6, a communication management machine 7 and an energy management system 8.

[0049] Each loop meter is connected to the communication management machine 7 respectively, and is connected to the energy management system 8 through the communication management machine 7.

[0050] Wherein: the photovoltaic unit 1 comprises a photovoltaic assembly 11, a first AC / DC module 12, a first circuit breaker S1 and a first meter 13 which are connected in sequence;

[0051] The energy storage unit 2 includes an energy storage battery 21, a second AC / DC module 22, a second circuit breaker S2 and a second meter 23 connected in sequence;

[0052] The solar-storage access unit 3 includes a third meter 31 and a third circuit breaker S3 connected in sequence;

[0053] The diesel generator unit 4 includes a diesel generator 41, a fourth meter 42 and a fourth circuit breaker S4 connected in sequence;

[0054] The photovoltaic unit 1, the energy storage unit 2, the photovoltaic storage access unit 3, and the diesel generating unit 4 constitute a photovoltaic storage diesel subsystem, which is connected to a dual power automatic switching device 5, wherein the photovoltaic unit 1 and the energy storage unit 2 are respectively connected to the dual power automatic switching device 5 through the photovoltaic storage access unit 3.

[0055] The charging pile unit 6 includes a fifth meter 61 , a fifth circuit breaker S5 and a charging pile device which are connected in sequence.

[0056] In order to ensure the charging demand and continuity of the charging piles, the dual power supply automatic switching device 5 of the photovoltaic storage and diesel charging microgrid system switches back and forth between the photovoltaic storage and diesel charging mode under the control of the energy management system 8.

[0057] The switching principle of the operating mode of the photovoltaic storage diesel charging microgrid system: the energy management system 8 obtains the data and status of the first AC / DC module 12, the energy storage battery 21, the second AC / DC module 22, the third circuit breaker S3, the diesel generator 41, the dual power automatic switching device 5 and each circuit meter in real time through the communication management machine 7, and then determines whether to switch the operating mode.

[0058] When photovoltaic and energy storage meet the needs of the charging pile, the dual power supply automatic switching device 5 switches to a photo-storage-charging circuit, and the energy management system 8 operates in a photo-storage-charging mode; when photovoltaic and energy storage cannot meet the needs of the charging pile, the dual power supply automatic switching device 5 switches to a diesel charging circuit, and the energy management system 8 operates in a diesel charging mode, while the photovoltaic storage subsystem operates independently.

[0059] Among them, photovoltaics and energy storage meet the needs of charging piles specifically as follows: the SOCState of Charge of the energy storage battery is greater than or equal to the lower limit SOCmin of the battery capacity. At this time, energy storage serves as the main power source together with photovoltaics to power the charging pile equipment.

[0060] The SOC of a storage battery represents the ratio between the energy stored in the battery and the energy that should be stored when fully charged.

[0061] Photovoltaic and energy storage cannot meet the needs of the charging pile, that is, the energy storage battery SOC is less than the lower limit SOCmin of the battery capacity. At this time, the photovoltaic storage system quits power supply, and the dual power automatic switching device 5 switches to the diesel charging mode, and the diesel generator 41 is used as the main power supply to power the charging pile equipment. The photovoltaic storage subsystem includes photovoltaic unit 1 and energy storage unit 2, which operate independently in independent modes. Photovoltaic unit 1 charges energy storage unit 2 when energy storage is the main power supply.

[0062] This embodiment also relates to a coordinated control method for an off-grid photovoltaic storage and diesel charging microgrid system, the method comprising:

[0063] In the photovoltaic charging and storage mode, the energy management system 8 determines whether the current photovoltaic power generation meets the charging power requirement of the charging pile by obtaining the photovoltaic power generation power Ppv of the first AC / DC 12, the operating power Pes of the second AC / DC 22 (including the operating power Pesc in the charging mode and the operating power Pesd in the discharging mode), the SOC of the energy storage battery 21, and the charging power Pch of the charging pile of the fifth meter 61, such as Figure 2 , specifically:

[0064] Step S11, obtaining in real time the photovoltaic power generation power Ppv of the first AC / DC 12, the operating power Pes of the second AC / DC 22, the SOC of the energy storage battery 21, and the charging pile charging power Pch of the fifth meter 61;

[0065] Step S12, when the photovoltaic power generation power Ppv is less than the charging power Pch of the charging pile, execute step S14; otherwise, determine whether the SOC of the energy storage battery 21 is less than the upper limit SOCmax of the remaining energy storage power. If yes, execute step S13, otherwise the photovoltaic unit 1 operates at a reduced power according to Ppv-Pch;

[0066] Step S13, if the photovoltaic power generation power Ppv is less than the sum of the charging power Pch of the charging pile and the rated power Pe of the energy storage, the photovoltaic unit 1 is preferentially supplied to the charging pile, and the energy storage unit 2 is charged according to the difference between the photovoltaic power generation power Ppv and the charging power Pch of the charging pile; if the photovoltaic power generation power Ppv ≥ the sum of the charging power Pch of the charging pile and the rated power of the energy storage, the photovoltaic unit 1 is preferentially supplied to the charging pile, and the energy storage unit 2 is charged according to the rated power Pe of the energy storage, and the remaining photovoltaic power Ppv-Pch-Pe is discarded, that is, the photovoltaic power is reduced, and the process returns to step S11;

[0067] Step S14, when the photovoltaic power generation power Ppv is less than the charging power Pch of the charging pile, if the charging power Pch of the charging pile is ≤ the sum of the photovoltaic power generation power Ppv and the energy storage rated power Pe, execute step S15, otherwise execute step S16;

[0068] Step S15, the photovoltaic unit 1 is supplied to the charging pile first, and the energy storage unit 2 is discharged according to the difference between the photovoltaic power generation power Ppv and the charging power Pch of the charging pile, and the process returns to step S11;

[0069] Step S16, if the charging power Pch of the charging pile is greater than the sum of the photovoltaic power generation power Ppv and the energy storage rated power Pe, the photovoltaic unit 1 is supplied to the charging pile first, and the energy storage unit 2 is discharged according to the rated power Pe. The remaining charging power Pch-Ppv-Pe is used to reduce the power of the charging pile to achieve dynamic balance in the light storage and charging mode, and then return to step S11.

[0070] In the diesel charging mode, the energy management system 8 obtains the photovoltaic power Ppv of the first AC / DC 12 and the operating power Pes of the second AC / DC 22 (corresponding to the charging mode). Figure 2 and Figure 3 Pesc in discharge mode corresponds to Figure 2 and Figure 3 Pesd in), the state SOC of the energy storage battery 21, and the charging power Pch of the charging pile of the fifth meter 61, to determine whether the current diesel power generation meets the charging power demand of the charging pile, such as Figure 3 , specifically:

[0071] Step S21, obtaining in real time the photovoltaic power Ppv of the first AC / DC 12, the operating power Pes of the second AC / DC 22, the state SOC of the energy storage battery 21, and the charging power Pch of the charging pile of the fifth meter 61;

[0072] Step S22, determine whether the rated power Pcfe of the diesel generator is greater than the charging power Pch of the charging pile. If yes, the output power Pcf of the diesel generator follows the charging power Pch of the charging pile; return to step S21; otherwise, execute step S23;

[0073] Step S23, the diesel generator outputs according to the rated power Pcfe, and the difference between the charging power Pch of the charging pile and the rated power Pcfe of the diesel generator is processed by reducing the power of the charging pile; return to step S21.

[0074] In diesel charging mode, the photovoltaic storage subsystem operates independently. Photovoltaic unit 1 charges energy storage unit 2 with energy storage as the main power source until the SOC of energy storage battery 21 is greater than or equal to the upper limit SOCmax of the remaining energy storage power or the photovoltaic power generation power Ppv is greater than or equal to the charging power Pch of the charging pile, and then it switches to photovoltaic storage charging mode.

[0075] The switching between the solar energy storage charging mode and the diesel charging mode is realized by the energy management system 8 and the dual power automatic switching device 5. Figure 4 , the switching conditions are as follows:

[0076] When the photovoltaic power generation power Ppv is greater than the charging power of the charging pile Pch, or the SOC of the energy storage battery 21 is greater than or equal to the upper limit SOCmax of the remaining energy storage power, the energy management system 8 sends a control instruction to the dual power automatic switching device 5 to make it operate in the photovoltaic storage charging mode, exit the diesel charging mode, and shut down the diesel generator 41;

[0077] like Figure 4 When the SOC of the energy storage battery 21 is less than or equal to the lower limit SOCmin of the remaining energy storage capacity, the energy management system 8 sends a control instruction to the dual power automatic switching device 5 to make it operate in the diesel charging mode and exit the light storage charging mode.

[0078] In the light storage and charging mode, in order to prevent the SOC of the energy storage battery 21 from reaching the SOC lower limit SOCmin, and the diesel generator 41 is not started, resulting in the problem of being unable to ensure the continuity of power supply, the near lower limit SOCminL of the energy storage battery 21 is set; Figure 4 When SOC is less than SOCminL, the energy management system 8 starts the diesel generator 41 to make it run. When SOC continues to drop to the lower limit SOCmin, that is, SOC≤SOCmin, the photovoltaic storage system stops supplying power and the dual power automatic switching device switches to the diesel charging mode; if SOC>SOCmin, it remains in the photovoltaic storage charging mode.

[0079] The process of reducing the power of the charging pile: first, the energy management system 8 calculates the power value that needs to be reduced for the charging pile; secondly, the power reduction value of each charging pile is calculated based on the current number of charging piles N and the rated power of the charging piles; finally, the energy management system 8 sends a power reduction instruction to the charging pile to achieve dynamic power balance.

[0080] The process of photovoltaic power reduction: first, the power value that needs to be reduced by the photovoltaic inverter is calculated through the energy management system 8; secondly, the power reduction value of each photovoltaic inverter is calculated according to the current number of photovoltaic inverters N and the rated power of the photovoltaic inverter, and finally, the energy management system 8 sends a power reduction instruction to the photovoltaic inverter to achieve dynamic power balance.

[0081] The electronic device of the present invention includes a central processing unit (CPU), which can perform various appropriate actions and processes according to computer program instructions stored in a read-only memory (ROM) or loaded from a storage unit into a random access memory (RAM). In the RAM, various programs and data required for device operation can also be stored. The CPU, ROM and RAM are connected to each other via a bus. An input / output (I / O) interface is also connected to the bus.

[0082] Multiple components in the device are connected to the I / O interface, including: input units, such as keyboards, mice, etc.; output units, such as various types of displays, speakers, etc.; storage units, such as disks, optical disks, etc.; and communication units, such as network cards, modems, wireless communication transceivers, etc. The communication unit allows the device to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunication networks.

[0083] The processing unit performs the various methods and processes described above, such as methods S11 to S16. For example, in some embodiments, methods S11 to S16 may be implemented as a computer software program, which is tangibly contained in a machine-readable medium, such as a storage unit. In some embodiments, part or all of the computer program may be loaded and / or installed on the device via a ROM and / or a communication unit. When the computer program is loaded into the RAM and executed by the CPU, one or more steps of methods S11 to S16 described above may be performed. Alternatively, in other embodiments, the CPU may be configured to execute methods S11 to S16 in any other appropriate manner (e.g., by means of firmware).

[0084] The functions described above herein may be performed at least in part by one or more hardware logic components. For example, without limitation, exemplary types of hardware logic components that may be used include: field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), complex programmable logic devices (CPLDs), and the like.

[0085] The program code for implementing the method of the present invention can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer or other programmable data processing device, so that the program code, when executed by the processor or controller, enables the functions / operations specified in the flow chart and / or block diagram to be implemented. The program code can be executed entirely on the machine, partially on the machine, partially on the machine as a stand-alone software package and partially on a remote machine, or entirely on a remote machine or server.

[0086] In the context of the present invention, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or equipment. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or equipment, or any suitable combination of the foregoing. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0087] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. An off-grid photovoltaic storage diesel charging microgrid system, the system comprising a photovoltaic unit (1) for photovoltaic power generation, an energy storage unit (2) for storing electricity, a charging pile unit (6), a photovoltaic storage access unit (3), a diesel generating unit (4) for diesel power generation, and a communication management machine (7), characterized in that: The system comprises an energy management system (8) and a dual power switching unit (5) respectively connected to a photovoltaic unit (1), an energy storage unit (2), a diesel generator unit (4) and a charging pile unit (6); The photovoltaic unit (1), energy storage unit (2), photovoltaic storage access unit (3), diesel generator unit (4) and charging pile unit (6) are respectively connected to the energy management system (8) through the communication management machine (7); The photovoltaic unit (1) and the energy storage unit (2) are respectively connected to the dual power supply switching unit (5) via the photovoltaic storage access unit (3); The dual power automatic switching device (5) realizes switching back and forth between the solar energy storage charging mode and the diesel charging mode under the control of the energy management system (8).

2. The off-grid solar-storage-diesel-charging microgrid system according to claim 1 is characterized in that: The photovoltaic unit (1) comprises a photovoltaic assembly (11), a first AC / DC module (12) and a first meter (13) which are connected in sequence; The energy storage unit (2) comprises an energy storage battery (21), a second AC / DC module (22) and a second meter (23) which are connected in sequence; The photovoltaic storage access unit (3) comprises a third meter (31) and a third circuit breaker (S3) connected in sequence; The diesel generator unit (4) comprises a diesel generator (41) and a fourth meter (42) which are connected in sequence; The charging pile unit (6) comprises a fifth meter (61), a fifth circuit breaker (S5) and a charging pile device which are connected in sequence.

3. The off-grid solar-storage-diesel-charging microgrid system according to claim 2 is characterized in that: The energy management system (8) acquires data and status of each unit and the dual power automatic switching device (5) in real time through the communication management machine (7), and then determines whether to switch the operation mode; wherein each unit includes the data and status of the first AC / DC module (12), the energy storage battery (21), the second AC / DC module (22), the third circuit breaker (S3), the diesel generator (41), the dual power automatic switching device (5) and each loop meter.

4. The off-grid solar-storage-diesel-charging microgrid system according to claim 3 is characterized in that: The determination of whether to switch the operation mode is specifically as follows: If the SOC of the energy storage battery is greater than the lower limit SOCmin of the battery capacity, it is judged that photovoltaic and energy storage meet the needs of the charging pile, and the dual power automatic switching device (5) switches to the photovoltaic storage charging circuit, and the energy management system (8) operates in the photovoltaic storage charging mode; otherwise, the dual power automatic switching device (5) switches to the diesel charging circuit, and the energy management system (8) operates in the diesel charging mode, and the diesel generator (41) is used as the main power supply to power the charging pile equipment, and the photovoltaic storage subsystem operates independently, wherein the photovoltaic storage subsystem includes a photovoltaic unit (1) and an energy storage unit (2).

5. The off-grid solar-storage-diesel-charging microgrid system according to claim 4 is characterized in that: A lower limit SOCminL is set for the energy storage battery (21). When the SOC of the energy storage battery is less than SOCminL, the energy management system (8) starts the diesel generator (41) to make it run. When the SOC of the energy storage battery is less than or equal to SOCmin, the photovoltaic storage subsystem stops supplying power, and the dual power automatic switching device switches to the diesel charging mode; otherwise, the mode is not switched.

6. A coordinated control method for an off-grid photovoltaic storage and diesel charging microgrid system using any one of claims 1 to 5, characterized in that: The method includes a coordinated control process in a photovoltaic storage and charging mode, including: Step S11, real-time acquisition of real-time data of each unit of the photovoltaic storage diesel charging microgrid system; Step S12, when the photovoltaic power generation power Ppv is less than the charging power Pch of the charging pile, step S14 is executed; otherwise, it is determined whether the SOC of the energy storage battery (21) is less than or equal to the upper limit SOCmax of the remaining energy storage power. If so, step S13 is executed, otherwise the photovoltaic unit (1) operates at a reduced power according to Ppv-Pch; Step S13, if the photovoltaic power generation power Ppv is less than the sum of the charging power Pch of the charging pile and the rated power Pe of the energy storage, the photovoltaic unit (1) is preferentially supplied to the charging pile, and the energy storage unit (2) is charged according to the difference between the photovoltaic power generation power Ppv and the charging power Pch of the charging pile; if the photovoltaic power generation power Ppv ≥ the sum of the charging power Pch of the charging pile and the rated power Pe of the energy storage, the photovoltaic unit (1) is preferentially supplied to the charging pile, and the energy storage unit (2) is charged according to the rated power Pe of the energy storage, and the remaining photovoltaic power Ppv-Pch-Pe is discarded, that is, the photovoltaic unit (1) operates at a reduced power according to Ppv-Pch-Pe, and the process returns to step S11; Step S14: if the charging pile charging power Pch is less than or equal to the sum of the photovoltaic power generation power Ppv and the energy storage rated power Pe, execute step S15; otherwise, execute step S16; Step S15, the photovoltaic unit (1) supplies the charging pile first, and the energy storage unit (2) discharges according to the difference between the charging power Pch of the charging pile and the photovoltaic power generation power Ppv, and returns to step S11; In step S16, the photovoltaic unit (1) is supplied to the charging pile first, the energy storage unit (2) is discharged according to the rated power Pe, and the remaining charging power Pch-Ppv-Pe is used to reduce the power of the charging pile to achieve a dynamic balance in the photovoltaic charging and storage mode, and then the process returns to step S11.

7. The method according to claim 6, characterized in that The method also includes a coordinated control method in a diesel charging mode, comprising: Step S21, real-time data of each unit of the photovoltaic storage diesel charging microgrid system is obtained in real time; Step S22, judging whether the rated power Pcfe of the diesel generator is greater than the charging power Pch of the charging pile, if so, the output power Pcf of the diesel generator follows the charging power Pch of the charging pile, and returning to step S21; otherwise, executing step S23; Step S23, the diesel generator outputs according to the rated power Pcfe, and the difference between the charging power Pch of the charging pile and the rated power Pcfe of the diesel generator is processed by reducing the power of the charging pile, and then returns to step S21.

8. The method according to claim 7, characterized in that The method also includes the following steps: in the diesel charging mode, the photovoltaic storage subsystem operates independently: When the photovoltaic power generation power Ppv is greater than the energy storage rated power Pe, the energy storage unit (2) is charged according to the Ppv value; otherwise, the energy storage unit (2) is charged according to the Pe value, and the photovoltaic unit (1) reduces power according to Ppv-Pe.

9. The method according to claim 6, characterized in that The method also includes a switching process between a photovoltaic storage and charging mode and a diesel charging mode: in the diesel charging mode, when the photovoltaic power generation power Ppv is greater than the charging power Pch of the charging pile, or the SOC of the energy storage battery (21) is greater than or equal to the upper limit SOCmax of the remaining energy storage power, the dual power automatic switching device (5) issues a control instruction to operate in the photovoltaic storage and charging mode, exit the diesel charging mode, and the diesel generator (41) is shut down; In the light-storage-charging mode, when the SOC of the energy storage battery (21) is less than the SOC lower limit SOCminL, the diesel generator (41) is started to run, and it is determined whether the SOC of the energy storage battery (21) is ≤ the lower limit SOCmin of the remaining energy storage capacity. If so, the light-storage system stops supplying power, and the dual power automatic switching device switches to the diesel charging mode; otherwise, it remains in the light-storage-charging mode.

10. An electronic device comprising a memory and a processor, wherein a computer program is stored in the memory, wherein: When the processor executes the program, the method according to any one of claims 6 to 9 is implemented.

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