Optical storage micro-grid system and constraint control method thereof, electronic equipment and storage medium

Abstract

The invention relates to the technical field of power electronic control, and discloses an optical storage micro-grid system and a constraint control method thereof, electronic equipment and a storage medium, the optical storage micro-grid system integrating photovoltaic and energy storage stability is configured, and a photovoltaic inverter in the optical storage micro-grid system is controlled to carry out MPPT (maximum power point tracking) so as to realize stable photovoltaic power output; particularly, the grid-connected scene and the off-grid scene are distinguished by monitoring the on-off condition of a mains supply change-over switch in real time, and on this basis, the photovoltaic scene condition and the real-time load condition are combined to perform respective constraint control on the optical storage micro-grid system in the grid-connected scene and the off-grid scene, so that the stable operation of the optical storage micro-grid system is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronic control, and in particular to a photovoltaic-storage microgrid system, a constraint control method therefor, an electronic device, and a computer-readable storage medium. Background Art

[0002] A microgrid refers to a small power generation and distribution system composed of distributed power sources, energy storage devices, energy conversion devices, loads, monitoring and protection devices, etc. Generally speaking, a microgrid is an autonomous system that can achieve self-control, protection, and management, and can either operate in parallel with the external power grid or operate independently. For example, a common one is a photovoltaic-storage microgrid. In recent years, although the application of photovoltaic-storage microgrids in the power system has become more and more extensive, due to the actual factors such as the gradually complex operation scenarios and the gradually diverse operation modes of photovoltaic-storage microgrids, the stability of photovoltaic-storage microgrids during operation has been greatly challenged. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems in the related art to some extent. For this purpose, the present invention provides a photovoltaic-storage microgrid system, a constraint control method therefor, an electronic device, and a storage medium, which can achieve the stable operation of the photovoltaic-storage microgrid system.

[0004] In a first aspect, an embodiment of the present invention provides a photovoltaic-storage microgrid system, including an energy storage inverter, a photovoltaic inverter, an isolation transformer, a battery unit, a photovoltaic unit, and a mains switch. Among them, the battery unit is connected to the mains switch through the energy storage inverter, the photovoltaic unit is sequentially connected to the mains switch through the photovoltaic inverter and the isolation transformer, the AC port of the energy storage inverter is connected to the AC port of the photovoltaic inverter through the isolation transformer, the mains switch is used to connect the mains input, and a load port for load power supply is provided between the mains switch and the isolation transformer.

[0005] In a second aspect, an embodiment of the present invention provides a constraint control method for the photovoltaic-storage microgrid system as described in the first aspect, including the following steps: Step S1, controlling the photovoltaic inverter to perform MPPT maximum power point tracking and real-time monitoring of the opening and closing conditions of the mains switch; Step S2, if the mains switch is in the closed state, generating a grid-connected constraint control strategy for the photovoltaic-storage microgrid system according to the magnitude relationship between the obtained photovoltaic power and the load power in combination with the current mains electricity price, otherwise executing step S3; Wherein, the photovoltaic power is obtained by the photovoltaic inverter converting the DC energy input by the photovoltaic unit, and the load power is the power required for the load operation monitored through the load port; Step S3: Generate an off-grid constraint control strategy for the photovoltaic energy storage microgrid system according to the magnitude relationship between the obtained photovoltaic power and the load power.

[0006] Optionally, in an embodiment of the present invention, the steps in step S2, generating a grid-connected constraint control strategy for the photovoltaic energy storage microgrid system according to the magnitude relationship between the obtained photovoltaic power and the load power in combination with the electricity price of the mains power in real time, include the following steps: Step S21: When the photovoltaic power is greater than or equal to the load power and the electricity price of the mains power is at the peak time, control the energy storage converter to enter the standby state, and supply power to the load independently based on the photovoltaic power, and feed the power back to the grid with the first photovoltaic surplus power, where the first photovoltaic surplus power is the difference between the photovoltaic power and the load power; Or, Step S22: When the photovoltaic power is less than the load power and the electricity price of the mains power is at the peak time, control the energy storage converter to enter the discharging state to output the discharging power, and supply power to the load in a hybrid manner based on the photovoltaic power and the discharging power, where the discharging power is the difference between the load power and the photovoltaic power; Or, Step S23: When the photovoltaic power is greater than or equal to the load power and the electricity price of the mains power is at the valley time, supply power to the load independently based on the photovoltaic power, and control the energy storage converter to enter the charging state, and charge the energy storage converter based on the first photovoltaic surplus power; Or, Step S24: When the photovoltaic power is less than the load power and the electricity price of the mains power is at the valley time, control the energy storage converter to enter the standby state, and supply power to the load independently based on the mains power.

[0007] Optionally, in an embodiment of the present invention, when the first photovoltaic surplus power is greater than the charging power required by the energy storage converter, after the step of charging the energy storage converter based on the first photovoltaic surplus power in step S23, the following steps are further included: Step S231: Control the energy storage converter to enter the standby state, and feed the power back to the grid with the second photovoltaic surplus power, where the second photovoltaic surplus power is the difference between the first photovoltaic surplus power and the charging power.

[0008] Optionally, in an embodiment of the present invention, step S3 includes the following steps: Step S31: When the photovoltaic power is less than the load power, control the energy storage converter to enter the discharging state to output discharging power, and perform hybrid power supply for the load based on the photovoltaic power and the discharging power, where the discharging power is the difference between the load power and the photovoltaic power; Or, Step S32: When the photovoltaic power is greater than or equal to the load power, perform independent power supply for the load based on the photovoltaic power, and control the energy storage converter to enter the charging state, and charge the energy storage converter based on the first photovoltaic surplus power, where the first photovoltaic surplus power is the difference between the photovoltaic power and the load power.

[0009] Optionally, in an embodiment of the present invention, when the first photovoltaic surplus power is greater than the charging power required by the energy storage converter, step S32 further includes the following steps: Step S321: Obtain the AC bus voltage of the energy storage converter through the AC port of the energy storage converter; Step S322: Perform power output control on the photovoltaic inverter according to the magnitude relationship between the AC bus voltage and a pre-determined AC bus rated voltage and an AC bus threshold voltage, where the AC bus threshold voltage is greater than the AC bus rated voltage.

[0010] Optionally, in an embodiment of the present invention, step S322 includes the following steps: Step S3221: When the AC bus voltage is less than or equal to the AC bus rated voltage, control the photovoltaic inverter to output the rated power of the photovoltaic inverter; or when the AC bus voltage is greater than or equal to the AC bus threshold voltage, control the photovoltaic inverter not to output power; or when the AC bus voltage is greater than the AC bus rated voltage and less than the AC bus threshold voltage, control the photovoltaic inverter to output variable power, where the variable power linearly decreases within the range from the rated power of the photovoltaic inverter to zero over time.

[0011] Optionally, in an embodiment of the present invention, when the energy storage converter adopts a current-limiting charging method, step S32 further includes the following steps: Step S323: Control the energy storage converter to maintain the AC bus voltage at according to the charging power and the rated power of the photovoltaic inverter, where The expression of is as follows: is the AC bus rated voltage, is the threshold voltage of the AC busbar, is the charging power, is the rated power of the PV inverter, is the rated power of the energy storage converter, is the current-limiting charging parameter, .

[0012] In a third aspect, an embodiment of the present invention provides an electronic device, including: at least one processor; at least one memory for storing at least one program; When at least one of the programs is executed by at least one of the processors, the constraint control method of the PV-storage microgrid system as described in the second aspect is implemented.

[0013] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, in which a program executable by a processor is stored, and when the program executable by the processor is executed by the processor, it is used to implement the constraint control method of the PV-storage microgrid system as described in the second aspect.

[0014] The PV-storage microgrid system and its constraint control method, electronic device, and storage medium proposed by the present invention not only configure a PV-storage microgrid system that integrates the stability of PV and energy storage, but also control the PV inverter therein to perform MPPT maximum power point tracking to achieve stable PV power output. In particular, by real-time monitoring the opening and closing conditions of the mains switch therein to distinguish grid-connected and off-grid scenarios, on this basis, combined with the PV scenario conditions and real-time load conditions, the PV-storage microgrid system is respectively constrained and controlled in grid-connected and off-grid scenarios, thereby realizing the stable operation of the PV-storage microgrid system. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic block diagram of the structure of a PV-storage microgrid system provided by an embodiment of the present invention; Figure 2 is a flowchart of the constraint control method of the PV-storage microgrid system provided by an embodiment of the present invention; Figure 3 is a flowchart after the step "charging the energy storage converter based on the first PV surplus power" in step S23 provided by an embodiment of the present invention; Figure 4 is a flowchart of step S32 provided by an embodiment of the present invention; Figure 5 is Figure 4 a flowchart of step S322 in Figure 6 is a schematic structural diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0017] It should be noted that although functional module division is performed in the device schematic diagram and the logical sequence is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order from the module division in the device or the sequence in the flowchart.

[0018] Figure 1 It is a structural schematic block diagram of a photovoltaic-storage microgrid system provided by an embodiment of the present invention.

[0019] As Figure 1 shown, the photovoltaic-storage microgrid system may but is not limited to include: a energy storage converter 100, a photovoltaic inverter 300, an isolation transformer 500, a battery unit 200, a photovoltaic unit 400, and a mains switch 600; Among them, the battery unit 200 is connected to the mains switch 600 through the energy storage converter 100, the photovoltaic unit 400 is sequentially connected to the mains switch 600 through the photovoltaic inverter 300 and the isolation transformer 500, the AC port of the energy storage converter 100 is connected to the AC port of the photovoltaic inverter 300 through the isolation transformer 500, the mains switch 600 is used to connect the mains input, and a load port for load power supply is provided between the mains switch 600 and the isolation transformer 500.

[0020] The energy storage converter 100 is used to convert the DC energy of the battery unit 200 into AC energy and can realize bidirectional conversion of AC and DC energy; the photovoltaic inverter 300 is used to convert the DC energy of the photovoltaic unit 400 into AC energy and can realize unidirectional energy transmission from DC to AC; the AC ports of the energy storage converter 100 and the photovoltaic inverter 300 are isolated by the isolation transformer 500 to prevent mutual influence of AC coupling. That is to say, by configuring a photovoltaic-storage integrated photovoltaic-storage microgrid system, it is convenient to further effectively and reliably constrain and control the photovoltaic-storage microgrid system.

[0021] It is understandable that the specific specifications, parameters, etc. of the energy storage converter 100, photovoltaic inverter 300, isolation transformer 500, battery unit 200, photovoltaic unit 400, and mains switching switch 600 can be, but are not limited to, set accordingly according to the actual application scenario. This part is well-known to those skilled in the art and does not constitute the main inventive point of the present invention, so it will not be elaborated here. For example, the photovoltaic unit 400 can be, but is not limited to, a common PV panel; the mains switching switch 600 can be, but is not limited to, an STS, that is, a static transfer switch. As a grid-connected and off-grid switching switch, it is mainly used for the power supply switching of two power sources and is a common automatic power supply selection and switching system. Under normal working conditions, when the main power supply is within the normal voltage range, the load is always connected to the main power supply. When the main power supply fails, the load automatically switches to the standby power supply. After the main power supply returns to normal, the load automatically switches to the main power supply. Here, the "main power supply" is the mains power. In other words, when the mains power is normal, the STS is closed. Conversely, when the mains power is abnormal, the STS is opened.

[0022] The description of the photovoltaic energy storage microgrid system and application scenarios in the embodiments of the present invention is to more clearly illustrate the technical solutions of the embodiments of the present invention and does not constitute a limitation on the technical solutions provided by the embodiments of the present invention. With the evolution of the photovoltaic energy storage microgrid system and the emergence of new application scenarios, the technical solutions provided by the embodiments of the present invention are equally applicable to similar technical problems.

[0023] Those skilled in the art can understand that Figure 1 the photovoltaic energy storage microgrid system shown in does not constitute a limitation on the embodiments of the present invention and may include more or fewer components than shown, or combine some components, or have different component arrangements.

[0024] Figure 2 is a flowchart of the constraint control method for the photovoltaic energy storage microgrid system provided by an embodiment of the present invention. As Figure 2 shown, the constraint control method for the photovoltaic energy storage microgrid system may include, but is not limited to, steps S1 to S3.

[0025] Step S1: Control the photovoltaic inverter to perform MPPT maximum power point tracking and monitor the opening and closing status of the mains switching switch in real time; Step S2: If the mains switching switch is in the closed state, generate a grid-connected constraint control strategy for the photovoltaic energy storage microgrid system based on the magnitude relationship between the obtained photovoltaic power and load power combined with the current mains electricity price, otherwise execute step S3; Among them, the photovoltaic power is obtained by converting the DC energy input by the photovoltaic unit by the photovoltaic inverter, and the load power is the power required for the load operation monitored through the load port; Step S3: Generate an off-grid constraint control strategy for the photovoltaic energy storage microgrid system according to the magnitude relationship between the obtained photovoltaic power and the load power.

[0026] In this step, the photovoltaic inverter is controlled to perform MPPT (maximum power point tracking) to achieve stable photovoltaic power output. In particular, the on-off status of the mains switch is monitored in real time to distinguish between grid-connected and off-grid scenarios. On this basis, the photovoltaic energy storage microgrid system is separately constrained and controlled in grid-connected and off-grid scenarios in combination with the photovoltaic scenario and the real-time load situation, so as to realize the stable operation of the photovoltaic energy storage microgrid system.

[0027] In an embodiment of the present invention, the steps in step S2, according to the magnitude relationship between the obtained photovoltaic power and the load power and combined with the real-time mains electricity price, generate a grid-connected constraint control strategy for the photovoltaic energy storage microgrid system, which may but is not limited to including the following steps: Step S21: When the photovoltaic power is greater than or equal to the load power and the mains electricity price is at peak time, control the energy storage converter to enter the standby state, and supply power to the load separately based on the photovoltaic power, and feed the power back to the grid with the first photovoltaic surplus power, where the first photovoltaic surplus power is the difference between the photovoltaic power and the load power; Or, Step S22: When the photovoltaic power is less than the load power and the mains electricity price is at peak time, control the energy storage converter to enter the discharging state to output the discharging power, and supply power to the load in a hybrid manner based on the photovoltaic power and the discharging power, where the discharging power is the difference between the load power and the photovoltaic power; Or, Step S23: When the photovoltaic power is greater than or equal to the load power and the mains electricity price is at valley time, supply power to the load separately based on the photovoltaic power, and control the energy storage converter to enter the charging state, and charge the energy storage converter with the first photovoltaic surplus power; Or, Step S24: When the photovoltaic power is less than the load power and the mains electricity price is at valley time, control the energy storage converter to enter the standby state, and supply power to the load separately based on the mains electricity.

[0028] In this step, when the photovoltaic power is greater than or equal to the load power and the mains electricity price is at peak time, it means that the photovoltaic power at this time is sufficient to provide the load power, and the load can be supplied with power separately based on the photovoltaic power. At the same time, there is still a certain amount of surplus photovoltaic power. Since the mains electricity price is at peak time, it is not suitable to feed the power back to the grid through the mains electricity, but feed the power back to the grid with the first photovoltaic surplus power, so as to realize the grid-connected constraint control of the photovoltaic energy storage microgrid system; When the photovoltaic power is less than the load power and the electricity price of the mains is at the peak time, it indicates that the photovoltaic power at this time is not sufficient to fully supply the load power and can only supply part of the power. At the same time, since the electricity price of the mains is at the peak time, it is not suitable to feed electricity back to the grid through the mains. Instead, the energy storage converter is controlled to enter the discharging state to output the discharging power, and the discharging power is used to make up for the load power that cannot be provided by the photovoltaic. That is, based on the photovoltaic power and the discharging power, hybrid power supply is provided for the load, so as to realize the grid connection constraint control of the photovoltaic-storage microgrid system; When the photovoltaic power is greater than or equal to the load power and the electricity price of the mains is at the valley time, it indicates that the photovoltaic power at this time is sufficient to supply the load power. The load can be supplied with power separately based on the photovoltaic power. At the same time, the surplus photovoltaic power can be used to charge the energy storage converter, so as to realize the grid connection constraint control of the photovoltaic-storage microgrid system; When the photovoltaic power is less than the load power and the electricity price of the mains is at the valley time, it indicates that the photovoltaic power at this time is not sufficient to fully supply the load power. At the same time, since the electricity price of the mains is at the valley time, it is recommended to supply power through the mains, and both the photovoltaic power and the energy storage power are stored for standby. That is, the energy storage converter is controlled to enter the standby state, and the load is supplied with power separately based on the mains, so as to realize the grid connection constraint control of the photovoltaic-storage microgrid system.

[0029] It can be seen that in the case of grid connection, by comparing the relative magnitude relationship between the photovoltaic power and the load power and combining the valley-peak situation of the electricity price of the mains, the grid connection constraint control of the photovoltaic-storage microgrid system can be effectively and reliably carried out in the corresponding situation, which is beneficial to realizing the stable operation of the photovoltaic-storage microgrid system.

[0030] As Figure 3 shown in an embodiment of the present invention, when the first surplus photovoltaic power is greater than the charging power required by the energy storage converter, after the step of charging the energy storage converter based on the first surplus photovoltaic power in step S23, it may further include but is not limited to the following steps: Step S231: Control the energy storage converter to enter the standby state and feed electricity back to the grid with the second surplus photovoltaic power, where the second surplus photovoltaic power is the difference between the first surplus photovoltaic power and the charging power.

[0031] That is to say, if the first surplus photovoltaic power is greater than the charging power required by the energy storage converter, there is still a surplus of the first surplus photovoltaic power at this time. Therefore, it is not necessary to use the battery power stored in the energy storage converter, but directly use this part of the remaining second surplus photovoltaic power to feed electricity back to the grid, so as to realize the grid connection constraint control of the photovoltaic-storage microgrid system.

[0032] An embodiment of the present invention, step S3 may include but is not limited to the following steps: Step S31: When the photovoltaic power is less than the load power, control the energy storage converter to enter the discharging state to output discharging power, and perform hybrid power supply for the load based on the photovoltaic power and the discharging power. Here, the discharging power is the difference between the load power and the photovoltaic power. Or, Step S32: When the photovoltaic power is greater than or equal to the load power, perform independent power supply for the load based on the photovoltaic power, and control the energy storage converter to enter the charging state to charge the energy storage converter based on the first photovoltaic surplus power. Here, the first photovoltaic surplus power is the difference between the photovoltaic power and the load power.

[0033] In this step, when the photovoltaic power is less than the load power and the mains power is not connected, it indicates that the current photovoltaic power is not sufficient to fully supply the load power and can only supply part of the power. It is necessary to control the energy storage converter to enter the discharging state to output discharging power, and the discharging power is used to make up for the load power that cannot be provided by the photovoltaic. That is, perform hybrid power supply for the load based on the photovoltaic power and the discharging power, so as to achieve the off-grid constraint control of the photovoltaic-storage microgrid system; when the photovoltaic power is greater than or equal to the load power and the mains power is not connected, it indicates that the current photovoltaic power is sufficient to supply the load power. Independent power supply for the load can be performed based on the photovoltaic power, and at the same time, control the energy storage converter to enter the charging state, and the energy storage converter can be charged through the photovoltaic surplus power, so as to achieve the grid-connected constraint control of the photovoltaic-storage microgrid system.

[0034] As Figure 4 shown, in an embodiment of the present invention, when the first photovoltaic surplus power is greater than the charging power required by the energy storage converter, step S32 may further include, but is not limited to, the following steps: Step S321: Obtain the AC bus voltage of the energy storage converter through the AC port of the energy storage converter. Step S322: Perform power output control on the photovoltaic inverter according to the magnitude relationship between the AC bus voltage and the pre-determined AC bus rated voltage and the AC bus threshold voltage, where the AC bus threshold voltage is greater than the AC bus rated voltage.

[0035] In this step, considering the situation where the first photovoltaic surplus power is greater than the charging power required by the energy storage converter, that is, when the battery unit is full or the energy storage converter is current-limited for charging, at this time, the photovoltaic energy is in excess, which may cause the AC bus voltage to rise or even the system to collapse. By obtaining the AC bus voltage of the energy storage converter under real-time conditions, and then performing power output control on the photovoltaic inverter according to the magnitude relationship between the AC bus voltage and the pre-determined AC bus rated voltage and the AC bus threshold voltage, to avoid the abnormal rise of the AC bus voltage.

[0036] It should be noted that the rated voltage of the AC bus represents the rated normal operating condition of the AC bus, and the threshold voltage of the AC bus represents the critical normal operating condition. Therefore, generally speaking, the reasonable AC bus voltage should not exceed the threshold voltage of the AC bus. In actual scenarios, the rated voltages of different AC buses may be different, and correspondingly, the threshold voltage of the AC bus changes accordingly. For example, in a certain scenario, the threshold voltage of the AC bus is 1.1 times the rated voltage of the AC bus.

[0037] As Figure 5 shown, in an embodiment of the present invention, step S322 may but is not limited to include the following steps: Step S3221: When the AC bus voltage is less than or equal to the rated voltage of the AC bus, control the PV inverter to output the rated power of the PV inverter; or when the AC bus voltage is greater than or equal to the threshold voltage of the AC bus, control the PV inverter not to output power; or when the AC bus voltage is greater than the rated voltage of the AC bus and less than the threshold voltage of the AC bus, control the PV inverter to output a variable power, where the variable power linearly decreases within the range from the rated power of the PV inverter to zero over time.

[0038] In this step, when the AC bus voltage is less than or equal to the rated voltage of the AC bus, it indicates that the AC bus voltage is within the normal range at this time. Therefore, there is no need to overly limit the output power of the PV inverter, and the PV inverter is controlled to output the rated power of the PV inverter to ensure that the AC bus voltage is maintained within the normal range; when the AC bus voltage is greater than or equal to the threshold voltage of the AC bus, it indicates that the AC bus voltage has exceeded the normal range at this time, so it is necessary to limit the PV inverter from outputting power again to avoid abnormal increase in the AC bus voltage; when the AC bus voltage is greater than the rated voltage of the AC bus and less than the threshold voltage of the AC bus, it indicates that the AC bus voltage is within the critical range, indicating that a limited amount of PV energy can be output. Therefore, the PV inverter is controlled to output a variable power. Since the variable power linearly decreases within the range from the rated power of the PV inverter to zero over time, PV energy can be provided to the energy storage converter within a certain limit, and at the same time, abnormal increase in the AC bus voltage can be effectively avoided. The "time" here can be set according to the actual scenario, such as a custom unit time or a fixed time period, etc., and is not limited here.

[0039] In an embodiment of the present invention, when the energy storage converter adopts a current-limiting charging method, step S32 further includes the following steps: Step S323: Control the energy storage converter to maintain the AC bus voltage at , where The expression of is as follows: is the rated voltage of the AC bus, is the threshold voltage of the AC bus, is the charging power, is the rated power of the PV inverter, is the rated power of the energy storage converter, is the current-limiting charging parameter, .

[0040] It can be seen that when , it indicates that the charging power of the energy storage converter under current-limiting conditions has exceeded the rated power of the PV inverter. Then, even if there is an excess of PV energy, it is not easy to cause an abnormal increase in the AC bus voltage. Therefore, the AC bus voltage can be maintained at the rated voltage of the AC bus. On the contrary, it indicates that the excess PV energy may cause an abnormal increase in the AC bus voltage. Therefore, it is necessary to further limit the AC bus voltage of the energy storage converter to be lower to prevent an abnormal increase in the AC bus voltage.

[0041] It can be understood that it can be set accordingly according to the actual scenario, which is not limited here; when , the above formula can be simplified as: .

[0042] Figure 6 is a schematic structural diagram of an electronic device 1000 provided by an embodiment of the present invention. As Figure 6 shown, the electronic device 1000 includes a memory 1100 and a processor 1200. The number of the memory 1100 and the processor 1200 can be one or more, Figure 6 and one memory 1100 and one processor 1200 are taken as examples in Figure 6 ; the memory 1100 and the processor 1200 in the device can be connected through a bus or other means,

[0043] The memory 1100, as a computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as the program instructions / modules corresponding to the constraint control method of the PV and energy storage microgrid system provided by any embodiment of the present invention. The processor 1200 implements the above-mentioned constraint control method of the PV and energy storage microgrid system by running the software programs, instructions, and modules stored in the memory 1100.

[0044] The memory 1100 may mainly include a program storage area and a data storage area. Among them, the program storage area may store an operating system and application programs required for at least one function. In addition, the memory 1100 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other non-volatile solid-state storage devices. In some instances, the memory 1100 may further include a memory remotely provided with respect to the processor 1200, and these remote memories may be connected to the device through a network. Examples of the above network include but are not limited to the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0045] An embodiment of the present invention further provides a computer-readable storage medium storing computer-executable instructions for executing the constraint control method of the optical storage microgrid system provided in any embodiment of the present invention.

[0046] An embodiment of the present invention further provides a computer program product including a computer program or computer instructions. The computer program or computer instructions are stored in a computer-readable storage medium. A processor of a computer device reads the computer program or computer instructions from the computer-readable storage medium, and the processor executes the computer program or computer instructions, so that the computer device executes the constraint control method of the optical storage microgrid system provided in any embodiment of the present invention.

[0047] The electronic devices and application scenarios described in the embodiments of the present invention are for more clearly illustrating the technical solutions of the embodiments of the present invention, and do not constitute a limitation to the technical solutions provided by the embodiments of the present invention. Those skilled in the art can know that with the evolution of electronic devices and the emergence of new application scenarios, the technical solutions provided by the embodiments of the present invention are equally applicable to similar technical problems.

[0048] Those of ordinary skill in the art can understand that all or some of the steps in the methods disclosed above, and the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, and appropriate combinations thereof.

[0049] In a hardware implementation, the division between the functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component may have multiple functions, or one function or step may be executed by the cooperation of several physical components. Some or all physical components may be implemented as software executed by a processor (such as a central processing unit, a digital signal processor, or a microprocessor), or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or non-transitory medium) and a communication medium (or transitory medium). As is well known to those of ordinary skill in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information such as computer-readable instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disks (DVDs) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and that can be accessed by a computer. In addition, as is well known to those of ordinary skill in the art, communication media typically contain computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transmission mechanism, and may include any information delivery medium.

[0050] The terms "component", "module", "system", etc. used in this specification are used to denote a computer-related entity, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component may be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, or a computer. By way of illustration, an application running on a computing device and the computing device can both be components. One or more components may reside in a process or execution thread, and a component may be located on one computer or distributed between two or more computers. In addition, these components may execute from various computer-readable media on which various data structures are stored. Components may communicate, for example, by signals according to one or more data packets (such as data from two components interacting with each other from a local system, a distributed system, or another component across a network, such as the Internet interacting with other systems through signals) through local or remote processes.

Claims

1. A photovoltaic-storage microgrid system, characterized in that, It includes an energy storage converter, a PV inverter, an isolation transformer, a battery unit, a PV unit, and a mains switch. Among them, the battery unit is connected to the mains switch through the energy storage converter, the PV unit is sequentially connected to the mains switch through the PV inverter and the isolation transformer, the AC port of the energy storage converter is connected to the AC port of the PV inverter through the isolation transformer, the mains switch is used to connect the mains input, and a load port for load power supply is provided between the mains switch and the isolation transformer.

2. A constraint control method for the photovoltaic-storage microgrid system according to claim 1, characterized in that, It includes the following steps: Step S1: Control the PV inverter to perform MPPT maximum power point tracking and monitor the opening and closing status of the mains switch in real time; Step S2: If the mains switch is in the closed state, generate a grid-connected constraint control strategy for the PV-battery microgrid system according to the magnitude relationship between the obtained PV power and the load power combined with the real-time mains electricity price, otherwise execute Step S3; Among them, the PV power is obtained by the PV inverter converting the DC energy input by the PV unit, and the load power is the power required for the load operation monitored through the load port; Step S3: Generate an off-grid constraint control strategy for the PV-battery microgrid system according to the magnitude relationship between the obtained PV power and the load power.

3. According to the constraint control method for the photovoltaic-storage microgrid system described in claim 2, characterized in that, The steps in Step S2, generating a grid-connected constraint control strategy for the PV-battery microgrid system according to the magnitude relationship between the obtained PV power and the load power combined with the real-time mains electricity price, include the following steps: Step S21: When the PV power is greater than or equal to the load power and the mains electricity price is at the peak time, control the energy storage converter to enter the standby state and supply power to the load alone based on the PV power, and feed the power back to the grid with the first PV surplus power, where the first PV surplus power is the difference between the PV power and the load power; Or, Step S22: When the PV power is less than the load power and the mains electricity price is at the peak time, control the energy storage converter to enter the discharging state to output the discharging power, and supply power to the load in a hybrid manner based on the PV power and the discharging power, where the discharging power is the difference between the load power and the PV power; Or, Step S23: When the PV power is greater than or equal to the load power and the mains electricity price is at the valley time, supply power to the load alone based on the PV power, control the energy storage converter to enter the charging state, and charge the energy storage converter based on the first PV surplus power; Or, Step S24: When the PV power is less than the load power and the mains electricity price is at the valley time, control the energy storage converter to enter the standby state and supply power to the load alone based on the mains electricity.

4. According to the constraint control method for the photovoltaic-storage microgrid system described in claim 3, characterized in that, When the first PV surplus power is greater than the charging power required by the energy storage converter, after the step in Step S23 of charging the energy storage converter based on the first PV surplus power, it further includes the following steps: Step S231: Control the energy storage converter to enter the standby state and feed power into the grid with the second photovoltaic surplus power, where the second photovoltaic surplus power is the difference between the first photovoltaic surplus power and the charging power.

5. According to the constraint control method for the photovoltaic-storage microgrid system described in claim 2, characterized in that, Step S3 includes the following steps: Step S31: When the photovoltaic power is less than the load power, control the energy storage converter to enter the discharging state to output the discharging power, and perform hybrid power supply for the load based on the photovoltaic power and the discharging power, where the discharging power is the difference between the load power and the photovoltaic power; Or, Step S32: When the photovoltaic power is greater than or equal to the load power, perform single power supply for the load based on the photovoltaic power, and control the energy storage converter to enter the charging state to charge the energy storage converter with the first photovoltaic surplus power, where the first photovoltaic surplus power is the difference between the photovoltaic power and the load power.

6. According to the constraint control method for the photovoltaic-storage microgrid system described in claim 5, characterized in that, When the first photovoltaic surplus power is greater than the charging power required by the energy storage converter, step S32 further includes the following steps: Step S321: Obtain the AC bus voltage of the energy storage converter through the AC port of the energy storage converter; Step S322: Perform power output control on the photovoltaic inverter according to the magnitude relationship between the AC bus voltage and the pre-determined AC bus rated voltage and the AC bus threshold voltage, where the AC bus threshold voltage is greater than the AC bus rated voltage.

7. According to the constraint control method for the photovoltaic-storage microgrid system described in claim 6, characterized in that, Step S322 includes the following steps: Step S3221: When the AC bus voltage is less than or equal to the AC bus rated voltage, control the photovoltaic inverter to output the rated power of the photovoltaic inverter; or when the AC bus voltage is greater than or equal to the AC bus threshold voltage, control the photovoltaic inverter not to output power; or when the AC bus voltage is greater than the AC bus rated voltage and less than the AC bus threshold voltage, control the photovoltaic inverter to output a variable power, where the variable power linearly decreases within the range from the rated power of the photovoltaic inverter to zero over time.

8. According to the constraint control method for the photovoltaic-storage microgrid system described in claim 6, characterized in that, When the energy storage converter adopts a current-limiting charging method, step S32 further includes the following steps: Step S323: Control the energy storage converter to maintain the AC bus voltage at , where is expressed as follows: ； is the rated voltage of the AC bus, is the threshold voltage of the AC bus, is the charging power, is the rated power of the PV inverter, is the rated power of the energy storage converter, is the current-limiting charging parameter, .

9. An electronic device, characterized in that, Including: At least one processor; At least one memory for storing at least one program; When at least one of the at least one program is executed by at least one of the at least one processor, the constraint control method of the photovoltaic and energy storage microgrid system as described in any one of claims 2 to 8 is implemented.

10. A computer-readable storage medium, characterized in that, Wherein there is a program executable by the processor, and when the program executable by the processor is executed by the processor, it is used to implement the constraint control method of the photovoltaic and energy storage microgrid system as described in any one of claims 2 to 8.

Images