Energy control method, device and equipment of optical storage load micro-grid and medium

Abstract

The invention discloses an energy control method, device and equipment of an optical storage load micro-grid and a medium, and belongs to the technical field of optical storage load micro-grids, and the method comprises the steps: detecting the active power of a gateway in the optical storage load micro-grid at the current moment, and obtaining the target power; if the target power is larger than or equal to the reverse power control threshold value and smaller than the demand control threshold value, the energy storage system and the inverter system are regulated and controlled with the lowest power consumption cost and the maximum output of the power of the inverter system as the principle; if the target power is greater than or equal to the demand control threshold value, regulating and controlling the inverter system and the energy storage system according to the power supply requirement of the load by taking the power of the maximum output inverter system as a principle; and if the target power is smaller than the reverse power control threshold value, regulating and controlling the energy storage system and the inverter system according to the reverse power control threshold value and the target power. By using the method, the energy management of the optical storage load micro-grid can be matched with the actual demand of the user.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic-load-storage microgrids, and in particular to an energy control method, device, equipment and medium for a photovoltaic-load-storage microgrid. Background Art

[0002] A photovoltaic-load-storage microgrid is a microgrid that integrates photovoltaic power generation, energy storage system and load management. Through the photovoltaic-load-storage microgrid, efficient utilization and optimal configuration of energy can be achieved. Among them, energy management is the key factor for the safe, stable and efficient operation of the photovoltaic-load-storage microgrid.

[0003] In the existing technology, most of them manage the energy of the photovoltaic-storage-load microgrid based on a single device and target, and rarely consider the electricity cost, demand control and reverse power constraint to achieve photovoltaic-storage coordinated control, which cannot meet the actual needs of users. At present, there is no more effective solution to this technical problem. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide an energy control method, device, equipment and medium for a photovoltaic load storage microgrid to solve the problem that the existing technology only manages the energy of the photovoltaic load storage microgrid based on a single device and cannot meet the actual needs of users. The specific scheme is as follows:

[0005] In order to solve the above technical problems, the present invention provides an energy control method for a photovoltaic load storage microgrid, comprising:

[0006] Detecting the active power of a gateway in a photovoltaic load-storage microgrid at the current moment to obtain a target power; the photovoltaic load-storage microgrid comprises: an inverter system, an energy storage system, a load and the gateway;

[0007] If the target power is greater than or equal to the reverse power control threshold and less than the demand control threshold, the energy storage system and the inverter system are regulated based on the principle of minimizing the electricity cost and maximizing the output power of the inverter system; the reverse power control threshold and the demand control threshold are set according to the grid connection requirements and user requirements, respectively;

[0008] If the target power is greater than or equal to the demand control threshold, the inverter system and the energy storage system are regulated based on the principle of maximizing the power output of the inverter system and according to the power supply requirements of the load;

[0009] If the target power is less than the reverse power control threshold, the energy storage system and the inverter system are regulated according to the reverse power control threshold and the target power.

[0010] Preferably, the principle of maximizing the output power of the inverter system and regulating the inverter system and the energy storage system according to the power supply requirements of the load includes:

[0011] Determine the active power setting value of the first target inverter at the next moment according to the rated active power of the first target inverter, and determine the active power shortage of the gateway according to the target power and a preset gateway maintenance threshold; wherein the first target inverter is any inverter participating in the power-limited operation in the inverter system;

[0012] The active power setting value of the energy storage system at the next moment is determined according to the active power setting value of the energy storage system at the current moment, the active power shortage of the gateway and the maximum power of the energy storage system, and the operating state of the energy storage system is adjusted according to the active power setting value of the energy storage system at the next moment.

[0013] Preferably, regulating the energy storage system and the inverter system according to the reverse power control threshold and the target power includes:

[0014] The over-limit power value of the gateway is determined according to the target power and a preset reverse power maintenance threshold, and the energy storage system and the inverter system are regulated according to the over-limit power value of the gateway.

[0015] Preferably, regulating the energy storage system and the inverter system according to the over-limit power value of the gateway includes:

[0016] If only the energy storage system participates in the limited power operation, the active power setting value of the energy storage system at the next moment is determined according to the active power setting value of the energy storage system at the current moment, the over-limit power value of the threshold and the minimum power value of the energy storage system, and the operating state of the energy storage system is adjusted according to the active power setting value of the energy storage system at the next moment;

[0017] If only the inverter system participates in the power-limited operation, the actual active power value of the inverter system at the current moment is adjusted according to the priority of each inverter in the inverter system until the actual active power value of the inverter system at the current moment meets the over-limit power value of the threshold;

[0018] Determine the active setting value of the second target inverter at the next moment according to the active actual value of the second target inverter at the current moment and the active adjustment value of the second target inverter, and adjust the operation state of the second target inverter according to the active setting value of the second target inverter at the next moment; wherein the second target inverter is any inverter participating in the limited power operation in the inverter system; the active adjustment value of the second target inverter is a pre-set power value;

[0019] If both the energy storage system and the inverter system participate in power-limited operation, the active power setting value of the energy storage system at the next moment is determined according to the active power setting value of the energy storage system at the current moment, the over-limit power value of the threshold and the minimum power value of the energy storage system, and the operating state of the energy storage system is adjusted according to the active power setting value of the energy storage system at the next moment;

[0020] Determine the remaining power shortage of the gateway according to the active power setting value of the energy storage system at the current moment, the active power setting value of the energy storage system at the next moment and the over-limit power value of the gateway, and adjust the active power actual value of each inverter in the inverter system according to the remaining power shortage of the gateway and the priority of each inverter in the inverter system until the active power actual value of the inverter system at the current moment meets the remaining power shortage of the gateway;

[0021] Determine the active setting value of the third target inverter at the next moment according to the actual active value of the third target inverter at the current moment and the active adjustment value of the third target inverter, and adjust the operating state of the third target inverter according to the active setting value of the third target inverter at the next moment; wherein, the third target inverter is any inverter participating in power adjustment in the inverter system; the active adjustment value of the third target inverter is a pre-set power value.

[0022] Preferably, the energy storage system and the inverter system are regulated based on the principle of minimizing the electricity cost and maximizing the output power of the inverter system, including:

[0023] If the power grid is in a valley period or a deep valley period, charging the energy storage system;

[0024] Determine the active setting value of the energy storage system at the next moment according to the active setting value of the energy storage system at the current moment, the target power, the target setting value, the upper and lower power limits of the energy storage system, and the preset reverse power maintenance threshold and the gate maintenance threshold; wherein the target setting value is set according to the actual operation requirements of the photovoltaic load-storage microgrid;

[0025] If the power grid is in a peak period or a spike period, the active power shortage of the gateway is determined according to the target power and the gateway maintenance threshold, and the active power setting value of the energy storage system at the next moment is determined according to the active power shortage of the gateway;

[0026] If the power grid is in a normal period, determining whether there is a peak period and / or a spike period after the normal period of the power grid;

[0027] If not present, determining the active power setting value of the energy storage system at the next moment according to the reverse power maintenance threshold;

[0028] If so, the step of determining the active power setting value of the energy storage system at the next moment according to the active power setting value of the energy storage system at the current moment, the target power, the target setting value, the upper and lower power limits of the energy storage system, and the preset reverse power maintenance threshold and the gate maintenance threshold is executed;

[0029] Based on the principle of maximizing the power output of the inverter system, the active power setting value of the inverter system at the next moment is determined according to the active power setting value of the energy storage system at the current moment, the active power setting value of the energy storage system at the next moment, and the power supply demand of the load, and the active power setting value of the energy storage system at the next moment is re-determined according to the active power setting value of the energy storage system at the current moment and the active power setting value of the energy storage system at the next moment;

[0030] The operating state of the inverter system is adjusted according to the active power setting value of the inverter system at the next moment, and the operating state of the energy storage system is adjusted according to the active power setting value of the energy storage system at the next moment.

[0031] Preferably, determining the active power setting value of the energy storage system at the next moment according to the active power setting value of the energy storage system at the current moment, the target power, the target setting value, the upper and lower power limits of the energy storage system, and the preset reverse power maintenance threshold and the threshold maintenance threshold includes:

[0032] Determine the reverse power control value of the energy storage system at the next moment according to the active power setting value of the energy storage system at the current moment, the target power, the active power setting value, the reverse power maintenance threshold value and the minimum power value of the energy storage system;

[0033] Determine a threshold demand control value of the energy storage system at the next moment according to the active power setting value of the energy storage system at the current moment, the target power, the threshold maintenance threshold, the active power setting value and the maximum power of the energy storage system;

[0034] If the reverse power control value of the energy storage system at the next moment is equal to the threshold demand control value of the energy storage system at the next moment, then determining the active power setting value of the energy storage system at the next moment according to the active power setting value;

[0035] If the reverse power control value of the energy storage system at the next moment is not equal to the active power setting value, determining the active power setting value of the energy storage system at the next moment according to the reverse power control value of the energy storage system at the next moment;

[0036] If the threshold demand control value of the energy storage system at the next moment is not equal to the active power setting value, the active power setting value of the energy storage system at the next moment is determined according to the threshold demand control value of the energy storage system at the next moment.

[0037] Preferably, the principle of maximizing the power output of the inverter system is to determine the active power setting value of the inverter system at the next moment according to the active power setting value of the energy storage system at the current moment, the active power setting value of the energy storage system at the next moment, and the power supply demand of the load, and at the same time, re-determine the active power setting value of the energy storage system at the next moment according to the active power setting value of the energy storage system at the current moment and the active power setting value of the energy storage system at the next moment, including:

[0038] Determining whether there is an inverter in the inverter system that operates with limited power;

[0039] If there is an inverter in limited power operation in the inverter system, an inverter that meets a first preset condition is selected from the inverters in limited power operation to obtain a first selected inverter, and the first selected inverter is controlled to be in an MPPT operation mode; wherein the actual active power value of the first selected inverter at the current moment is less than zero, or the active power setting value of the first selected inverter at the current moment is greater than or equal to zero, and the difference between the active power setting value of the first selected inverter at the current moment and the actual active power value of the first selected inverter at the current moment is greater than or equal to a preset value;

[0040] Determining whether all inverters in the inverter system are in the MPPT operation mode;

[0041] If yes, adjusting the operating state of the energy storage system according to the active power setting value of the energy storage system at the next moment;

[0042] If not, then select an inverter that meets the second preset condition from the inverters in power-limited operation to obtain a target set, and determine the power adjustment value of the energy storage system according to the active power setting value of the energy storage system at the next moment and the active power setting value of the energy storage system at the current moment; wherein the second selected inverter is any inverter in the target set; the active power setting value of the second selected inverter at the current moment is greater than or equal to zero, and the difference between the active power setting value of the second selected inverter at the current moment and the active power actual value of the second selected inverter at the current moment is less than the preset value;

[0043] Calculating a difference between the target power and the reverse power maintenance threshold to obtain a target difference;

[0044] When the power adjustment value of the energy storage system is greater than zero;

[0045] If the target difference is greater than zero, determining the active power shortage of the gateway according to the target power, the reverse power maintenance threshold and the power adjustment value of the energy storage system;

[0046] If the target difference is less than or equal to zero, setting the active power deficit of the gateway to zero;

[0047] Determining the active power setting value of the second screening inverter at the next moment according to the active power shortage of the gateway and the active actual value of each inverter in the target set at the current moment;

[0048] When the power adjustment value of the energy storage system is less than zero;

[0049] If the target difference is greater than zero, determining the active power shortage of the gateway according to the target power, the reverse power maintenance threshold and the power adjustment value of the energy storage system;

[0050] If the target difference is less than or equal to zero, determining the active power shortage of the gateway according to the power adjustment value of the energy storage system;

[0051] Determining the active power setting value of the second screening inverter at the next moment according to the active power shortage of the gateway, the actual active power value of each inverter in the target set at the current moment, and the rated active power of the inverter;

[0052] When the power adjustment value of the energy storage system is equal to zero;

[0053] Determine the active power deficit of the gateway according to the target power and the reverse power maintenance threshold, and determine the active power setting value of the second screening inverter at the next moment according to the active power deficit of the gateway, the actual active power value of each inverter in the target set at the current moment, and the rated active power of the inverter;

[0054] The active power setting value of the energy storage system at the next moment is re-determined according to the power adjustment value of the energy storage system, the active power setting value of the energy storage system at the current moment and the active power setting value of the energy storage system at the next moment.

[0055] In order to solve the above technical problems, the present invention also provides an energy control device for a photovoltaic load storage microgrid, comprising:

[0056] A power detection module is used to detect the active power of the gateway in the photovoltaic load-storage microgrid at the current moment to obtain the target power; the photovoltaic load-storage microgrid includes: an inverter system, an energy storage system, a load and the gateway;

[0057] A first control module is used to control the energy storage system and the inverter system based on the principle of minimizing the electricity cost and maximizing the output power of the inverter system if the target power is greater than or equal to the reverse power control threshold and less than the demand control threshold; the reverse power control threshold and the demand control threshold are set according to the grid connection requirements and user requirements of the power grid respectively;

[0058] A second control module is used for, if the target power is greater than or equal to the demand control threshold, to maximize the output power of the inverter system and to control the inverter system and the energy storage system according to the power supply requirement of the load;

[0059] The third control module is used to control the energy storage system and the inverter system according to the reverse power control threshold and the target power if the target power is less than the reverse power control threshold.

[0060] In order to solve the above technical problem, the present invention further provides an electronic device, comprising:

[0061] Memory for storing computer programs;

[0062] A processor is used to implement the steps of the energy control method of a photovoltaic load-storage microgrid disclosed above when executing the computer program.

[0063] In order to solve the above technical problems, the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the energy control method of a photovoltaic load-storage microgrid disclosed above are implemented.

[0064] Beneficial effect: It can be seen that in the present invention, the active power of the gateway in the photovoltaic load-storage microgrid at the current moment is first detected to obtain the target power; the photovoltaic load-storage microgrid includes: an inverter system, an energy storage system, a load and a gateway; if the target power is greater than or equal to the reverse power control threshold and less than the demand control threshold, the energy storage system and the inverter system are adjusted based on the principle of minimizing the electricity cost and maximizing the output power of the inverter system; the reverse power control threshold and the demand control threshold are set according to the grid connection requirements and user requirements of the power grid respectively; if the target power is greater than or equal to the demand control threshold, the inverter system and the energy storage system are adjusted based on the principle of maximizing the output power of the inverter system, and according to the power supply requirements of the load; if the target power is less than the reverse power control threshold, the energy storage system and the inverter system are adjusted according to the reverse power control threshold and the target power.

[0065] Because the active power of the gateway at the current moment can represent the power consumption of the photovoltaic load-storage microgrid, the reverse power control threshold can represent the limit value of the photovoltaic load-storage microgrid transmitting reverse power to the grid, and the demand control threshold can represent the limit value of the user's purchase of electricity from the grid, so in the process of coordinated control of the inverter system and the energy storage system according to the reverse power control threshold and the demand control threshold, the photovoltaic load-storage microgrid can be energy managed based on the electricity cost and anti-reverse flow control strategy, so that the energy management method of the photovoltaic load-storage microgrid can be matched with the actual needs of users.

[0066] Correspondingly, the energy control device, equipment and medium of the photovoltaic load storage microgrid provided by the present invention also have the above-mentioned beneficial effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0068] Figure 1 A flow chart of an energy control method for a photovoltaic load storage microgrid provided by an embodiment of the present invention;

[0069] Figure 2 This is the principle diagram of the photovoltaic load storage microgrid;

[0070] Figure 3 A flow chart of regulating an energy storage system and an inverter system in a photovoltaic load-storage microgrid provided by an embodiment of the present invention when the active power of a gateway at the current moment is less than a reverse power control threshold;

[0071] Figure 4A flow chart of regulating an energy storage system and an inverter system when the active power of a gateway in a photovoltaic load-storage microgrid at the current moment is greater than or equal to a reverse power control threshold and less than a demand control threshold provided by an embodiment of the present invention;

[0072] Figure 5 A flow chart of regulating an energy storage system and an inverter system based on the principle of maximizing the output power of the inverter system provided by an embodiment of the present invention;

[0073] Figure 6 A structural diagram of an energy control device for a photovoltaic load storage microgrid provided by an embodiment of the present invention;

[0074] Figure 7 A structural diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0075] 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 only 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 are within the scope of protection of the present invention.

[0076] See also Figure 1 , Figure 1 A flow chart of an energy control method for a photovoltaic load storage microgrid provided by an embodiment of the present invention, the method comprising:

[0077] Step S11: Detect the active power of the gateway in the solar-load-storage microgrid at the current moment, obtain the target power, and determine whether the target power is greater than or equal to the demand control threshold; if so, execute step S12; if not, execute step S13;

[0078] The photovoltaic load-storage microgrid includes: an inverter system, an energy storage system, a load and a gateway; the reverse power control threshold and the demand control threshold are set according to the grid connection requirements and user requirements respectively;

[0079] Step S12: Based on the principle of maximizing the power output of the inverter system, the inverter system and the energy storage system are regulated according to the power supply requirements of the load;

[0080] Step S13: Determine whether the target power is less than the reverse power control threshold; if so, execute step S14; if not, execute step S15;

[0081] Step S14: regulating the energy storage system and the inverter system according to the reverse power control threshold and the target power;

[0082] Step S15: Based on the principle of minimizing the electricity cost and maximizing the output power of the inverter system, the energy storage system and the inverter system are regulated.

[0083] In this method, the reverse power control threshold Pgrid,ni,con and the demand control threshold Pgrid,xu,con need to be set in advance according to the grid connection requirements and user requirements; the reverse power control threshold is a protection value set to prevent the reverse power phenomenon in the grid. If Pgrid,t<Pgrid,ni,con, the photovoltaic load storage microgrid will trigger the protection action, thereby preventing the reverse power operation of the grid and ensuring the safe and stable operation of the grid and the photovoltaic load storage microgrid. The demand control threshold can represent the power value corresponding to the demand electricity fee value paid by the user to the grid. See Figure 2 , Figure 2 When the reverse power control threshold Pgrid,ni,con and the demand control threshold Pgrid,xu,con are set, the active power of the gateway in the photovoltaic load storage microgrid at the current moment is detected to obtain the target power Pgrid,t.

[0084] If Pgrid,ni,con≤Pgrid,t<Pgrid,xu,con, it means that there is no reverse flow in the grid, and the power value transmitted by the grid to the photovoltaic load storage microgrid does not exceed the user demand control threshold. At this time, it is necessary to regulate the energy storage system and the inverter system based on the principle of minimizing the electricity cost and maximizing the output power of the inverter system, so as to maximize the energy output by the inverter system to be consumed by the load in the photovoltaic load storage microgrid, and minimize the electricity cost of the photovoltaic load storage microgrid. Among them, the inverter system contains multiple inverters, and the inverter system is used to convert the energy output by photovoltaics, so that the power output by the inverter system can supply power to the load.

[0085] If Pgrid,t≥Pgrid,xu,con, it means that the power value transmitted by the grid to the photovoltaic load storage microgrid has exceeded the user demand control threshold. At this time, in order to allow the photovoltaic load storage microgrid to meet the power supply requirements of the load, there is no need to limit the output power of the inverter system, and the power output of the energy storage system needs to be increased. That is, in this case, it is only necessary to maximize the power output of the inverter system and regulate the inverter system and energy storage system according to the power supply requirements of the load.

[0086] If Pgrid,t<Pgrid,ni,con, it means that the power transmitted by the photovoltaic load storage microgrid to the grid is too large, and the grid has experienced reverse flow. At this time, it is necessary to limit the output power of the energy storage system and / or inverter system in the photovoltaic load storage microgrid to avoid reverse flow in the grid. In this case, it is necessary to regulate the energy storage system and inverter system according to the reverse power control threshold and target power.

[0087] Compared with the existing technology, because the active power of the gateway at the current moment can characterize the power consumption of the photovoltaic load-storage microgrid, the reverse power control threshold can characterize the limit value of the photovoltaic load-storage microgrid transmitting reverse power to the power grid, and the demand control threshold can characterize the limit value of the user's purchase of electricity from the power grid, so in the process of coordinated control of the inverter system and the energy storage system according to the reverse power control threshold and the demand control threshold, the photovoltaic load-storage microgrid can be energy managed based on the electricity cost and anti-reverse flow control strategy, so that the energy management method of the photovoltaic load-storage microgrid can be matched with the actual needs of users.

[0088] Based on the above embodiment, this embodiment further illustrates and optimizes the technical solution. As a preferred implementation method, the above steps are based on the principle of maximizing the power output of the inverter system, and regulating the inverter system and the energy storage system according to the power supply requirements of the load, including:

[0089] Determine the active power setting value of the first target inverter at the next moment according to the rated active power of the first target inverter, and determine the active power shortage of the gateway according to the target power and the preset gateway maintenance threshold; wherein the first target inverter is any inverter participating in the power-limited operation in the inverter system;

[0090] The active power setting value of the energy storage system at the next moment is determined according to the active power setting value of the energy storage system at the current moment, the active power shortage at the threshold and the maximum power of the energy storage system, and the operating state of the energy storage system is adjusted according to the active power setting value of the energy storage system at the next moment.

[0091] In this embodiment, if Pgrid,t≥Pgrid,xu,con, it means that the power value transmitted by the power grid to the photovoltaic load-storage microgrid has exceeded the user demand control threshold. At this time, in order to enable the photovoltaic load-storage microgrid to meet the power supply requirements of the load, there is no need to limit the output power of the inverter system, and the power output of the energy storage system needs to be increased.

[0092] Specifically, the inverter in the inverter system in the limited power operation mode can be first found, and the first target inverter can be set as any inverter in the inverter system that participates in the limited power operation. In addition, the flag Flag_inv can be used to identify whether the first target inverter is in the limited power operation mode.

[0093] If the flag Flag_inv corresponding to the first target inverter is 0, it indicates that the first target inverter is in the MPPT (Maximum Power Point Tracking) operation mode; if the flag Flag_inv corresponding to the first target inverter is 1, it indicates that the first target inverter is in the limited power operation mode.

[0094] Assuming that the first target inverter is in the power-limited operation mode, Flag_inv is set to 0, P PV ,set,i,t+1=P PV ,max,i, where P PV ,set,i,t+1 is the active setting value of the first target inverter at the next moment, P PV ,max,i is the rated active power of the first target inverter.

[0095] Then, increase the power output of the energy storage system and calculate the active power shortage at the gateway: Pr,t=Pgrid,t-Pgrid,xu,wei, and let P ETC ,set,i,t+1=min{ P ETC ,set,t+|Pr,t|,P ETC ,max}.

[0096] Where Pr,t is the active power shortage of the gateway, Pgrid,t is the target power, Pgrid,xu,wei is the preset gateway demand maintenance threshold, P ETC ,set,i,t+1 is the active setting value of the energy storage system at the next moment, P ETC ,set,t is the active setting value of the energy storage system at the current moment, P ETC ,max is the maximum power value of the energy storage system.

[0097] Finally, according to the active setting value P of the energy storage system at the next moment ETC ,set,i,t+1 to adjust the operating status of the energy storage system. Specifically:

[0098] If P ETC ,set,t+1≥0, and SOC ETC,t <SOC ETC,xu,con , then for P ETC,set,t+1 to reset, that is, let P ETC ,set,t+1=0;

[0099] If P ETC ,set,t+1<0, and SOC ETC,t ≥SOC ETC,max , then for P ETC ,set,t+1 to reset, let P ETC ,set,t+1=0;

[0100] If P ETC ,set,t+1=0, then the energy storage system is in standby state;

[0101] In order to prevent the energy storage system from frequently performing charging and discharging actions, a dead zone interval can also be set, that is:

[0102] If | P ETC ,set,t+1- P ETC ,set,t|≤2%* P ETC ,set,t, then for P ETC ,set,t+1 to reset, that is, let P ETC ,set,t+1= P ETC ,set,t;

[0103] Among them, P ETC ,set,t+1 is the active setting value of the energy storage system at the next moment, P ETC ,set,t is the active setting value of the energy storage system at the current moment, SOC ETC,t is the SOC (State of Charge) of the energy storage system at the current moment. ETC,xu,con is the threshold demand control threshold of the energy storage system, which is a pre-set value. ETC,max is the maximum SOC of the energy storage system.

[0104] Obviously, through the technical solution provided in this embodiment, the output power of the inverter system can be absorbed to the maximum extent and the economic benefits of the photovoltaic load-storage microgrid can be improved.

[0105] Based on the above embodiment, this embodiment further illustrates and optimizes the technical solution. As a preferred implementation mode, the above step of regulating the energy storage system and the inverter system according to the reverse power control threshold and the target power includes:

[0106] The over-limit power value of the gateway is determined according to the target power and the preset reverse power maintenance threshold, and the energy storage system and the inverter system are adjusted according to the over-limit power value of the gateway.

[0107] In this embodiment, if Pgrid,t<Pgrid,ni,con, it means that the power transmitted by the photovoltaic load storage microgrid to the grid is too large, and the grid will have a reverse flow phenomenon. In this case, in order to reduce the power transmitted by the photovoltaic load storage microgrid to the grid, it is necessary to reduce the power output of the inverter system and / or energy storage system in the photovoltaic load storage microgrid.

[0108] Specifically, it is necessary to first determine the over-limit power value Pr,t of the gateway based on the target power Pgrid,t and the pre-set reverse power maintenance threshold Pgrid,ni,wei. The over-limit power value Pr,t of the gateway can represent the amount of power that the target power Pgrid,t exceeds the reverse power maintenance threshold Pgrid,ni,wei; then, the energy storage system and the inverter system are regulated according to the over-limit power value Pr,t of the gateway, so that the active power of the gateway can be maintained at the reverse power maintenance threshold.

[0109] Obviously, the technical solution provided in this embodiment can avoid the reverse flow phenomenon in the power grid.

[0110] See also Figure 3 , Figure 3 A flowchart of regulating the energy storage system and the inverter system in a photovoltaic load-storage microgrid provided by an embodiment of the present invention when the active power of the gateway at the current moment is less than the reverse power control threshold. As a preferred implementation, the above step: regulating the energy storage system and the inverter system according to the over-limit power value of the gateway includes:

[0111] Step S01: If only the energy storage system participates in the power-limited operation, the active power setting value of the energy storage system at the next moment is determined according to the active power setting value of the energy storage system at the current moment, the over-limit power value of the threshold and the minimum power value of the energy storage system, and the operating state of the energy storage system is adjusted according to the active power setting value of the energy storage system at the next moment;

[0112] Step S02: If only the inverter system participates in the power-limited operation, the actual active power value of the inverter system at the current moment is adjusted according to the priority of each inverter in the inverter system until the actual active power value of the inverter system at the current moment meets the over-limit power value of the threshold;

[0113] Step S03: determining the active setting value of the second target inverter at the next moment according to the active actual value of the second target inverter at the current moment and the active adjustment value of the second target inverter, and adjusting the operating state of the second target inverter according to the active setting value of the second target inverter at the next moment; wherein the second target inverter is any inverter participating in the limited power operation in the inverter system; the active adjustment value of the second target inverter is a pre-set power value;

[0114] Step S04: If both the energy storage system and the inverter system participate in power-limited operation, the active power setting value of the energy storage system at the next moment is determined according to the active power setting value of the energy storage system at the current moment, the over-limit power value of the threshold, and the minimum power value of the energy storage system, and the operating state of the energy storage system is adjusted according to the active power setting value of the energy storage system at the next moment;

[0115] Step S05: determining the remaining power shortage of the gateway according to the active power setting value of the energy storage system at the current moment, the active power setting value of the energy storage system at the next moment and the over-limit power value of the gateway, and adjusting the active power actual value of each inverter in the inverter system according to the remaining power shortage of the gateway and the priority of each inverter in the inverter system, until the active power actual value of the inverter system at the current moment meets the remaining power shortage of the gateway;

[0116] Step S06: Determine the active setting value of the third target inverter at the next moment according to the actual active power value of the third target inverter at the current moment and the active power adjustment value of the third target inverter, and adjust the operating state of the third target inverter according to the active setting value of the third target inverter at the next moment; wherein the third target inverter is any inverter participating in power adjustment in the inverter system; the active power adjustment value of the third target inverter is a pre-set power value.

[0117] In actual applications, according to the user's setting requirements, in the photovoltaic load-storage microgrid, only the energy storage system may participate in the power-limited operation, only the inverter system may participate in the power-limited operation, or both the energy storage system and the inverter system may participate in the power-limited operation. Therefore, when regulating the energy storage system and the inverter system according to the over-limit power value Pr,t at the threshold, it is necessary to regulate the energy storage system and the inverter system in three cases.

[0118] Case 1: If only the energy storage system in the photovoltaic load-storage microgrid participates in the power-limited operation, the over-limit power value of the threshold is: Pr,t=Pgird,t-Pgrid,ni,wei<0. At this time, the active setting value of the energy storage system at the next moment is:

[0119] P ETC ,set,t+1=max{ P ETC ,set,t- | Pr,t |,P ETC , min};

[0120] Among them, P ETC ,set,t is the active setting value of the energy storage system at the current moment, Pr,t is the over-limit power value of the threshold, P ETC , min is the minimum power value of the energy storage system.

[0121] Then, according to the active setting value P of the energy storage system at the next moment ETC ,set,t+1 adjusts the operating status of the energy storage system, specifically:

[0122] If P ETC ,set,t+1≥0, and SOC ETC,t <SOC ETC,xu,con , then for P ETC ,set,t+1 to reset, that is, let P ETC ,set,t+1=0;

[0123] If P ETC ,set,t+1<0, and SOC ETC,t ≥SOC ETC,max , then for P ETC ,set,t+1 to reset, that is, let P ETC ,set,t+1=0;

[0124] If P ETC ,set,t+1=0, then the energy storage system is in standby state;

[0125] If | P ETC ,set,t+1- P ETC ,set,t|≤2%* P ETC ,set,t, then for P ETC ,set,t+1 to reset, that is, let P ETC ,set,t+1= P ETC ,set,t;

[0126] Among them, P ETC ,set,t+1 is the active setting value of the energy storage system at the next moment, P ETC ,set,t is the active setting value of the energy storage system at the current moment, SOC ETC,t is the SOC of the energy storage system at the current moment, SOC ETC,xu,con is the threshold demand control threshold of the energy storage system, which is a pre-set value. ETC,max is the maximum SOC of the energy storage system.

[0127] Case 2: If only the inverter system in the photovoltaic load-storage microgrid participates in the power-limited operation, the over-limit power value of the gateway is: Pr,t=Pgird,t-Pgrid,ni,wei<0. At this time, the actual active value of the inverter system at the current moment is adjusted according to the priority order of each inverter in the inverter system until the actual active value of the inverter system at the current moment meets the over-limit power value of the gateway, that is, PPV ,i,t≥| Pr,t |. Among them, P PV ,i,t is the sum of the output powers of all inverters participating in the power-limited operation in the inverter system, and Pr,t is the over-limit power value at the threshold.

[0128] Assuming that the second target inverter is any inverter in the inverter system that participates in power-limited operation, set Flag_inv_limit = 1, P PV ,set,j,t+1= max{P PV ,act,j,t- P PV ,set,j,t,0}; where P PV ,set,j,t+1 is the active setting value of the second target inverter at the next moment, P PV ,act,j,t is the actual active value of the second inverter at the current moment, P PV ,set,j,t is the active power adjustment of the second target inverter.

[0129] Scenario 3: If both the energy storage system and the inverter system in the photovoltaic load-storage microgrid participate in power operation, the over-limit power value of the threshold is: Pr,t=Pgird,t-Pgrid,ni,wei<0. At this time, it is necessary to reduce the discharge power of the energy storage system first, and then reduce the output power of the inverter system.

[0130] Specifically, let P ETC ,set,t+1=max{ P ETC ,set,t- | Pr,t |,P ETC , min}, and according to the active setting value P of the energy storage system at the next moment ETC ,set,t+1 adjusts the operating state of the energy storage system, that is:

[0131] If P ETC ,set,t+1≥0, and SOC ETC,t <SOC ETC,xu,con , then for P ETC ,set,t+1 to reset, that is, let P ETC ,set,t+1=0;

[0132] If P ETC ,set,t+1<0, and SOC ETC,t ≥SOC ETC,max , then for P ETC ,set,t+1 to reset, that is, let P ETC,set,t+1=0;

[0133] If P ETC ,set,t+1=0, then the energy storage system is in standby state;

[0134] If | P ETC ,set,t+1- P ETC ,set,t|≤2%* P ETC ,set,t, then for P ETC ,set,t+1 to reset, that is, let P ETC ,set,t+1= P ETC ,set,t;

[0135] Among them, P ETC ,set,t+1 is the active setting value of the energy storage system at the next moment, P ETC ,set,t is the active setting value of the energy storage system at the current moment, SOC ETC,t is the SOC of the energy storage system at the current moment, SOC ETC,xu,con is the threshold demand control threshold of the energy storage system, which is a pre-set value. ETC,max is the maximum SOC of the energy storage system, P ETC , min is the minimum power value of the energy storage system.

[0136] Then, calculate the remaining power deficit at the gateway Pr,t=| Pr,t |-| P ETC ,set,t+1- P ETC ,set,t|, Pr,t= max{ Pr, t, 0}, and limit the power of each inverter according to the priority order of each inverter in the inverter system, and accumulate P PV ,act,k,t≥ Pr,t, where P PV ,act,k,t is the cumulative power value of the output power of each inverter participating in the power-limited operation, Pr,t is the remaining power deficit at the threshold.

[0137] At the same time, let P PV ,set,k,t+1=max{P PV ,act,k,t - P PV ,set,k,t+1,0}, where P PV,set,k,t+1 is the active setting value of the third target inverter at the next moment, P PV ,act,k,t is the actual active value of the third inverter at the current moment, P PV ,set,k,t+1 is the active power adjustment value of the third target inverter. Then, according to the active power setting value P of the third target inverter at the next moment PV ,set,k,t+1 adjusts the operating state of the third target inverter.

[0138] Specifically, if P PV ,set,k,t+1≥P PV ,max,k, then for P PV ,set,k,t+1 to reset, that is, let P PV ,set,k,t+1=P PV ,max,k. Among them, P PV ,max,k is the maximum power value of the third target inverter.

[0139] Obviously, through the technical solution provided in this embodiment, the energy storage system and the inverter system can be regulated more accurately and reverse flow in the power grid can be avoided.

[0140] Based on the above embodiments, this embodiment further illustrates and optimizes the technical solution. Figure 4 , Figure 4 A flowchart of regulating the energy storage system and the inverter system when the active power of the gateway in a photovoltaic load-storage microgrid at the current moment is greater than or equal to the reverse power control threshold and less than the demand control threshold is provided in an embodiment of the present invention. As a preferred implementation, the above steps: regulating the energy storage system and the inverter system based on the principle of minimizing the electricity cost and maximizing the output power of the inverter system, include:

[0141] Step S201: If the power grid is in a valley period or a deep valley period, charging the energy storage system;

[0142] Step S202: Determine the active setting value of the energy storage system at the next moment according to the active setting value of the energy storage system at the current moment, the target power, the target setting value, the upper and lower power limits of the energy storage system, and the preset reverse power maintenance threshold and the gate maintenance threshold; wherein the target setting value is set according to the actual operation requirements of the photovoltaic load-storage microgrid;

[0143] Step S203: If the power grid is in a peak period or a peak period, the active power shortage of the gateway is determined according to the target power and the gateway maintenance threshold, and the active power setting value of the energy storage system at the next moment is determined according to the active power shortage of the gateway;

[0144] Step S204: if the power grid is in a normal period, determine whether there is a peak period and / or a peak period after the normal period of the power grid;

[0145] Step S205: If it does not exist, determine the active power setting value of the energy storage system at the next moment according to the reverse power maintenance threshold;

[0146] Step S206: If it exists, then the step of determining the active setting value of the energy storage system at the next moment according to the active setting value of the energy storage system at the current moment, the target power, the target setting value, the upper and lower power limits of the energy storage system, and the preset reverse power maintenance threshold and the gate maintenance threshold is executed;

[0147] Step S207: Based on the principle of maximizing the power output of the inverter system, the active setting value of the inverter system at the next moment is determined according to the active setting value of the energy storage system at the current moment, the active setting value of the energy storage system at the next moment, and the power supply demand of the load, and the active setting value of the energy storage system at the next moment is re-determined according to the active setting value of the energy storage system at the current moment and the active setting value of the energy storage system at the next moment;

[0148] Step S208: adjusting the operating state of the inverter system according to the active power setting value of the inverter system at the next moment, and adjusting the operating state of the energy storage system according to the active power setting value of the energy storage system at the next moment.

[0149] In this embodiment, when Pgrid,ni,con≤Pgrid,t<Pgrid,xu,con, the energy storage system and the inverter system are regulated based on the principle of minimizing the electricity cost and maximizing the output inverter power. Specifically, if the power grid is in a valley period or a deep valley period, the energy storage system is charged. The purpose of charging the energy storage system is to supply power to the load in the photovoltaic load storage microgrid during the peak period of the power grid to reduce the user's electricity cost.

[0150] In the process of charging the energy storage system, it is necessary to set the active power setting value P of the energy storage system at the current moment. ETC ,set,t, target power Pgrid,t, target setting value d, maximum power of energy storage system P ETC ,max, the minimum power P of the energy storage system ETC ,min, (the maximum power and the minimum power of the energy storage system are the upper and lower power limits of the energy storage system) and the gate maintenance threshold Pgrid,ni,wei to determine the active setting value P of the energy storage system at the next moment ETC ,set,t+1.

[0151] It should be noted that when determining the active setting value P of the energy storage system at the next moment, ETC,set,t+1, we need to pay attention not only to the active setting value of the energy storage system at the next moment that will not cause reverse flow in the power grid, but also to the active setting value of the energy storage system at the next moment that will not exceed the user demand control threshold. At the same time, we also need to pay attention to the active setting value of the energy storage system at the next moment that cannot exceed the upper and lower power limits of the energy storage system.

[0152] If the power grid is in the peak period or spike period, let Pr,t=Pgrid,t-max{Pgrid,ni,wei,0}, where Pr,t is the active power shortage of the gateway, Pgrid,t is the target power, and Pgrid,ni,wei is the gateway maintenance threshold.

[0153] If 0≤Pr,t, then let P ETC ,set,t+1=min{P ETC ,set,t+|Pr,t|,P ETC , max};

[0154] If Pr,t<0, then let P ETC ,set,t+1=max{P ETC ,set,t-|Pr,t|,P ETC , min};

[0155] Among them, Pr,t is the active power shortage at the threshold, P ETC ,set,t+1 is the active setting value of the energy storage system at the next moment, P ETC ,set,t is the active setting value of the energy storage system at the current moment, P ETC , max is the maximum power of the energy storage system, P ETC , min is the minimum power of the energy storage system.

[0156] If the grid is in a normal period, it is necessary to further determine whether there is a peak period and / or a peak period after the normal period of the grid. If there is no peak period and / or a peak period after the normal period of the grid, the active power setting value P of the energy storage system at the next moment is determined according to the reverse power maintenance threshold Pgrid,ni,wei. ETC ,set,t+1, at this time, the energy storage system is in the discharge state or standby state. If there is a peak period and / or a spike period after the normal period of the power grid, the active setting value of the energy storage system at the next moment can be determined according to the active setting value, target power, target setting value, upper and lower power limits of the energy storage system at the current moment, and the preset reverse power maintenance threshold and gate maintenance threshold.

[0157] Since the inverter in the inverter system is in a limited power operation state, it will affect the service life of the inverter. Therefore, when determining the active power setting value P of the energy storage system at the next moment, ETC ,set,t+1, it is also necessary to maximize the output power of the inverter system and set the active power of the energy storage system at the current moment P ETC ,set,t, the active power setting value P of the energy storage system at the next moment ETC ,set,t+1 and the power supply requirement of the load determine the active power setting value of the inverter system at the next moment.

[0158] After determining the active setting value of the inverter system at the next moment, in order to ensure that the active setting value of the energy storage system at the next moment is accurate, feasible and reasonable, it is also necessary to re-determine the active setting value of the energy storage system at the next moment based on the active setting value of the energy storage system at the current moment and the active setting value of the energy storage system at the next moment.

[0159] After determining the active power setting value of the inverter system at the next moment and the active power setting value of the energy storage system at the next moment, the operating state of the inverter system can be adjusted according to the active power setting value of the inverter system at the next moment, and the operating state of the energy storage system can be adjusted according to the active power setting value of the energy storage system at the next moment.

[0160] Obviously, the technical solution provided by this embodiment can reduce the user's electricity cost.

[0161] As a preferred implementation, the above step of determining the active power setting value of the energy storage system at the next moment according to the active power setting value of the energy storage system at the current moment, the target power, the target setting value, the upper and lower power limits of the energy storage system, and the preset reverse power maintenance threshold and the gate maintenance threshold includes:

[0162] Determine the reverse power control value of the energy storage system at the next moment according to the active setting value, target power, target setting value, reverse power maintenance threshold and minimum power value of the energy storage system at the current moment;

[0163] Determine the threshold demand control value of the energy storage system at the next moment according to the active setting value, target power, threshold maintenance threshold, target setting value and maximum power of the energy storage system at the current moment;

[0164] If the reverse power control value of the energy storage system at the next moment is equal to the threshold demand control value of the energy storage system at the next moment, the active power setting value of the energy storage system at the next moment is determined according to the active power setting value;

[0165] If the reverse power control value of the energy storage system at the next moment is not equal to the active power setting value, then the active power setting value of the energy storage system at the next moment is determined according to the reverse power control value of the energy storage system at the next moment;

[0166] If the threshold demand control value of the energy storage system at the next moment is not equal to the active power setting value, the active power setting value of the energy storage system at the next moment is determined according to the threshold demand control value of the energy storage system at the next moment.

[0167] In this embodiment, when the power grid is in a valley period or a deep valley period, two key variables need to be introduced in the process of charging the energy storage system, namely: the reverse power control value P of the energy storage system at the next moment; ETC ,set,t+1,ni and the threshold demand control value P of the energy storage system at the next moment ETC ,set,t+1,xu.

[0168] Let P ETC ,set,t+1,xu=min{max{ P ETC ,set,t+ Pgrid,t-Pgrid,xu,wei,d},P ETC ,max};

[0169] P ETC ,set,t+1,ni=max{min{P ETC ,set,t+ Pgrid,t-max{Pgrid,ni,wei,0},d},P ETC ,min};

[0170] Among them, P ETC ,set,t+1,ni is the reverse power control value of the energy storage system at the next moment, P ETC ,set,t is the active setting value of the energy storage system at the current moment, Pgrid,t is the target power, Pgrid,xu,wei is the reverse power maintenance threshold, P ETC ,min is the minimum power of the energy storage system, P ETC ,set,t+1,xu is the threshold demand control value of the energy storage system at the next moment, P ETC ,max is the maximum power of the energy storage system, and d is the active power setting value. It should be noted that the active power setting value d corresponds to different power values ​​in different operation stages of the power grid.

[0171] If P ETC ,set,t+1,ni=P ETC ,set,t+1,xu,then let P ETC ,set,t+1=d;

[0172] If PETC ,set,t+1,ni≠d, then let P ETC ,set,t+1= P ETC ,set,t+1,ni;

[0173] If P ETC ,set,t+1,xu≠d, then let P ETC ,set,t+1=P ETC ,set,t+1,xu.

[0174] Obviously, through the technical solution provided in this embodiment, the active power setting value of the energy storage system at the next moment can be accurately determined in the charging scenario of the energy storage system.

[0175] See also Figure 5 , Figure 5 A flowchart for regulating the energy storage system and the inverter system based on the principle of maximizing the output power of the inverter system provided by an embodiment of the present invention. As a preferred implementation, the above step S207: based on the principle of maximizing the output power of the inverter system, and determining the active power setting value of the inverter system at the next moment according to the active power setting value of the energy storage system at the current moment, the active power setting value of the energy storage system at the next moment and the power supply demand of the load, and re-determining the active power setting value of the energy storage system at the next moment according to the active power setting value of the energy storage system at the current moment and the active power setting value of the energy storage system at the next moment, includes:

[0176] Step S101: determining whether there is an inverter in the inverter system that operates with limited power;

[0177] Step S102: If there is an inverter operating with limited power in the inverter system, an inverter satisfying a first preset condition is selected from the inverters operating with limited power to obtain a first selected inverter, and the first selected inverter is controlled to be in the MPPT operation mode; wherein the actual active power value of the first selected inverter at the current moment is less than zero, or the active power setting value of the first selected inverter at the current moment is greater than or equal to zero, and the difference between the active power setting value of the first selected inverter at the current moment and the actual active power value of the first selected inverter at the current moment is greater than or equal to the preset value;

[0178] Step S103: determining whether all inverters in the inverter system are in the MPPT operation mode;

[0179] Step S104: If yes, the operating state of the energy storage system is adjusted according to the active power setting value of the energy storage system at the next moment;

[0180] Step S105: If not, then select an inverter that meets the second preset condition from the inverters in power-limited operation to obtain a target set, and determine the power adjustment value of the energy storage system according to the active power setting value of the energy storage system at the next moment and the active power setting value of the energy storage system at the current moment; wherein the second selected inverter is any inverter in the target set; the active power setting value of the second selected inverter at the current moment is greater than or equal to zero, and the difference between the active power setting value of the second selected inverter at the current moment and the active power actual value of the second selected inverter at the current moment is less than the preset value;

[0181] Step S106: Calculate the difference between the target power and the reverse power maintenance threshold to obtain a target difference;

[0182] Step S107: when the power adjustment value of the energy storage system is greater than zero;

[0183] Step S108: If the target difference is greater than zero, the active power shortage of the gateway is determined according to the target power, the reverse power maintenance threshold and the power adjustment value of the energy storage system;

[0184] Step S109: If the target difference is less than or equal to zero, the active power deficit of the gateway is set to zero;

[0185] Step S110: determining the active power setting value of the second screening inverter at the next moment according to the active power shortage of the gateway and the active actual value of each inverter in the target set at the current moment;

[0186] Step S111: when the power adjustment value of the energy storage system is less than zero;

[0187] Step S112: if the target difference is greater than zero, determining the active power shortage of the gateway according to the target power, the reverse power maintenance threshold and the power adjustment value of the energy storage system;

[0188] Step S113: if the target difference is less than or equal to zero, determining the active power shortage of the gateway according to the power adjustment value of the energy storage system;

[0189] Step S114: determining the active power setting value of the second screening inverter at the next moment according to the active power shortage of the gateway, the actual active power value of each inverter in the target set at the current moment, and the rated active power of the inverter;

[0190] Step S115: when the power adjustment value of the energy storage system is equal to zero;

[0191] Step S116: determining the active power deficit of the gateway according to the target power and the reverse power maintenance threshold, and determining the active power setting value of the second screening inverter at the next moment according to the active power deficit of the gateway, the actual active power value of each inverter in the target set at the current moment, and the rated active power of the inverter;

[0192] Step S117: re-determine the active power setting value of the energy storage system at the next moment according to the power adjustment value of the energy storage system, the active power setting value of the energy storage system at the current moment and the active power setting value of the energy storage system at the next moment.

[0193] In this embodiment, when determining the active power setting value of the inverter system and the active power setting value of the energy storage system at the next moment, it is first necessary to determine whether there is an inverter operating with limited power in the inverter system.

[0194] If there are inverters operating with limited power in the inverter system, inverters meeting the first preset condition are screened from the inverters operating with limited power to obtain first screened inverters, and the first screened inverters are controlled to be in the MPPT operation mode.

[0195] That is, in P PV ,set,m,t≥0 and P PV ,set,m,tP PV ,act,m,t ≥5%* P PV ,set,m,t,or,P PV ,act,m,t<0, the first screening inverter is controlled to be in MPPT operation mode. PV ,set,m,t is the active setting value of the first screening inverter at the current moment, P PV ,act,m,t is the actual active value of the first filter inverter at the current moment, 5%* P PV ,set,m,t is the preset value.

[0196] Then, it is determined whether all inverters in the inverter system are in the MPPT operation mode. If all inverters in the inverter system are in the MPPT operation mode, the operation state of the energy storage system is adjusted according to the active power setting value of the energy storage system at the next moment. That is:

[0197] If P ETC ,set,t+1≥0, and SOC ETC,t <SOC ETC,xu,con , then for P ETC ,set,t+1 to reset, that is, let P ETC ,set,t+1=0;

[0198] If P ETC ,set,t+1<0, and SOC ETC,t ≥SOC ETC,max , then for P ETC ,set,t+1 to reset, that is, let P ETC ,set,t+1=0;

[0199] If P ETC ,set,t+1=0, then the energy storage system is in standby state;

[0200] If | P ETC ,set,t+1- P ETC ,set,t|≤2%* P ETC ,set,t, then for P ETC ,set,t+1 to reset, that is, let P ETC ,set,t+1= P ETC ,set,t;

[0201] Among them, P ETC ,set,t+1 is the active setting value of the energy storage system at the next moment, P ETC ,set,t is the active setting value of the energy storage system at the current moment, SOC ETC,t is the SOC of the energy storage system at the current moment, SOC ETC,xu,con is the threshold demand control threshold of the energy storage system, which is a pre-set value. ETC,max is the maximum SOC of the energy storage system, P ETC , min is the minimum power value of the energy storage system.

[0202] If not all inverters in the inverter system are in MPPT operation mode (that is, if there are inverters in limited power operation in the inverter system), it is necessary to select inverters that meet the second preset condition from the inverters in limited power operation to obtain a target set, and determine the power adjustment value of the energy storage system based on the active power setting value of the energy storage system at the next moment and the active power setting value of the energy storage system at the current moment.

[0203] That is, in P PV ,set,n,t≥0 and P PV ,set,n,tP PV ,act,n,t <5%* P PV ,set,n,t, then the inverters operating with limited power are considered to meet the second preset condition, and the inverters meeting the second preset condition are defined as the target set Ψ. PV ,set,n,t is the active setting value of the second screening inverter at the current moment, P PV ,act,n,t is the actual active value of the second screening inverter at the current moment.

[0204] calculate P ETC ,set,t+1= P ETC,set,t+1- P ETC ,set,t, and determine the active power setting value P of the second screening inverter at the next moment PV ,set,n,t+1. Among them, P ETC ,set,t+1 is the power adjustment value of the energy storage system, P ETC ,set,t+1 is the active setting value of the energy storage system at the next moment, P ETC ,set,t is the active setting value of the energy storage system at the current moment.

[0205] Situation 1: When P ETC ,set,t+1>0;

[0206] If Pgrid,t-Pgrid,ni,wei>0 (Pgrid,t-Pgrid,ni,wei is the target difference), then let Pr,t=max{Pgrid,t-Pgrid,ni,wei, P ETC ,set,t+1};

[0207] If Pgrid,t-Pgrid,ni,wei≤0, then set Pr,t=0;

[0208] Then, the remaining active power deficit is allocated proportionally based on the actual power and rated power of each inverter in the target set, that is:

[0209] P PV ,set,n,t+1=[( P PV ,max,n,t- P PV ,set,n,t) / n∈Ψ ( P PV ,max,n,t- P PV ,set,n,t)]*Pr,t;

[0210] Let P PV ,set,n,t+1=min{P PV ,set,n,t+ P PV ,set,n,t+1,P PV ,max,n};

[0211] Situation 2: When P ETC ,set,t+1<0;

[0212] If Pgrid,t-Pgrid,ni,wei>0, then let Pr,t= Pgrid,t-Pgrid,ni,wei+| P ETC ,set,t+1|;

[0213] If Pgrid,t-Pgrid,ni,wei≤0, then let Pr,t=| P ETC ,set,t+1|;

[0214] Then, the remaining active power deficit is allocated proportionally based on the actual power and rated power of each inverter in the target set, that is:

[0215] P PV ,set,n,t+1=[( P PV ,max,n,t- P PV ,set,n,t) / n∈Ψ ( P PV ,max,n,t- P PV ,set,n,t)]*Pr,t;

[0216] Let P PV ,set,n,t+1=min{P PV ,set,n,t+ P PV ,set,n,t+1,P PV ,max,n};

[0217] Situation 3: When | P ETC ,set,t+1|=0;

[0218] Let Pr,t = max{Pgrid,t - Pgrid,ni,wei, 0}, and allocate the remaining active power deficit in proportion based on the actual power and rated power of each inverter in the target set, that is:

[0219] P PV ,set,n,t+1=[( P PV ,max,n,t- P PV ,set,n,t) / n∈Ψ ( P PV ,max,n,t- P PV ,set,n,t)]*Pr,t;

[0220] Let P PV,set,n,t+1=min{P PV ,set,n,t+ P PV ,set,n,t+1,P PV ,max,n};

[0221] In the above cases 1, 2 and 3, Pr,t is the active power shortage at the gateway, Pgrid,t is the target power, Pgrid,ni,wei is the reverse power maintenance threshold, P ETC ,set,t+1 is the power adjustment value of the energy storage system, P PV ,set,n,t+1 is the power adjustment value of the second screening inverter, P PV ,max,n,t is the maximum power of the second screened inverter, P PV ,set,n,t is the active setting value of the second screening inverter at the current moment, P PV ,set,n,t+1 is the active setting value of the second screening inverter at the next moment.

[0222] Situation 4: When P ETC ,set,t+1≥0;

[0223] This indicates that the power output of the inverter system is insufficient. At this time, the power output of the energy storage system needs to be increased. Then, let: P ETC ,set,t+1= P ETC ,set,t+max{0, P ETC ,set,t- n∈Ψ (P PV ,max,nP PV ,set,n,t)}, or, for simplicity, let P ETC ,set,t+1=P ETC ,set,t.

[0224] Situation 5: When P ETC ,set,t+1<0;

[0225] Keep P ETC ,set,t+1 remains unchanged, and then according to the active setting value P of the energy storage system at the next moment ETC ,set,t+1 adjusts the operating state of the energy storage system. That is:

[0226] If P ETC ,set,t+1≥0, and SOC ETC,t<SOC ETC,xu,con , then for P ETC ,set,t+1 to reset, that is, let P ETC ,set,t+1=0;

[0227] If P ETC ,set,t+1<0, and SOC ETC,t ≥SOC ETC,max , then for P ETC ,set,t+1 to reset, that is, let P ETC ,set,t+1=0;

[0228] If P ETC ,set,t+1=0, then the energy storage system is in standby state;

[0229] If | P ETC ,set,t+1- P ETC ,set,t|≤2%* P ETC ,set,t, then for P ETC ,set,t+1 to reset, that is, let P ETC ,set,t+1= P ETC ,set,t;

[0230] Among them, P ETC ,set,t+1 is the active setting value of the energy storage system at the next moment, P ETC ,set,t is the active setting value of the energy storage system at the current moment, SOC ETC,t is the SOC of the energy storage system at the current moment, SOC ETC,xu,con is the threshold demand control threshold of the energy storage system, which is a pre-set value. ETC,max is the maximum SOC of the energy storage system, P ETC , min is the minimum power value of the energy storage system.

[0231] Obviously, through the technical solution provided in this embodiment, not only can the power-limited operation mode and the MPPT operation mode of each inverter in the inverter system be flexibly switched according to the actual operation conditions of the photovoltaic load-storage microgrid, thereby achieving precise control of the active power of the inverter system, but also precise regulation of the energy storage system can be achieved.

[0232] See also Figure 6 , Figure 6 A structural diagram of an energy control device for a photovoltaic load storage microgrid provided by an embodiment of the present invention, the device comprising:

[0233] The power detection module 21 is used to detect the active power of the gateway in the photovoltaic load-storage microgrid at the current moment to obtain the target power; the photovoltaic load-storage microgrid includes: an inverter system, an energy storage system, a load and the gateway;

[0234] A first control module 22 is used to control the energy storage system and the inverter system based on the principle of minimizing the electricity cost and maximizing the output power of the inverter system if the target power is greater than or equal to the reverse power control threshold and less than the demand control threshold; the reverse power control threshold and the demand control threshold are set according to the grid connection requirements and user requirements respectively;

[0235] A second control module 23 is used to control the inverter system and the energy storage system based on the principle of maximizing the power output of the inverter system if the target power is greater than or equal to the demand control threshold, and according to the power supply requirement of the load;

[0236] The third control module 24 is configured to control the energy storage system and the inverter system according to the reverse power control threshold and the target power if the target power is less than the reverse power control threshold.

[0237] An energy control device for a photovoltaic-load-storage microgrid provided in an embodiment of the present invention has the beneficial effects of the energy control method for a photovoltaic-load-storage microgrid disclosed above.

[0238] See also Figure 7 , Figure 7 A structural diagram of an electronic device provided by an embodiment of the present invention, the device includes:

[0239] A memory 31, used for storing computer programs;

[0240] The processor 32 is used to implement the steps of the energy control method of the photovoltaic load-storage microgrid disclosed above when executing the computer program.

[0241] An electronic device provided by an embodiment of the present invention has the beneficial effects of the energy control method of the aforementioned photovoltaic load storage microgrid.

[0242] Correspondingly, an embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the energy control method of a photovoltaic load-storage microgrid disclosed above are implemented.

[0243] A computer-readable storage medium provided in an embodiment of the present invention has the beneficial effects of the energy control method of a photovoltaic load-storage microgrid disclosed above.

[0244] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0245] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0246] The above is a detailed introduction to the energy control method, device, equipment and medium of a photovoltaic load-storage microgrid provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for general technicians in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. An energy control method for a photovoltaic load storage microgrid, characterized in that: include: Detect the active power of the gateway in the solar-load storage microgrid at the current moment and obtain the target power; The photovoltaic load-storage microgrid comprises: an inverter system, an energy storage system, a load and the gateway; If the target power is greater than or equal to the reverse power control threshold and less than the demand control threshold, the energy storage system and the inverter system are regulated based on the principle of minimizing the electricity cost and maximizing the output power of the inverter system; the reverse power control threshold and the demand control threshold are set according to the grid connection requirements and user requirements, respectively; If the target power is greater than or equal to the demand control threshold, the inverter system and the energy storage system are regulated based on the principle of maximizing the power output of the inverter system and according to the power supply requirements of the load; If the target power is less than the reverse power control threshold, the energy storage system and the inverter system are regulated according to the reverse power control threshold and the target power.

2. The energy control method of a photovoltaic load storage microgrid according to claim 1 is characterized in that: The principle of maximizing the output power of the inverter system and regulating the inverter system and the energy storage system according to the power supply requirements of the load includes: Determine the active power setting value of the first target inverter at the next moment according to the rated active power of the first target inverter, and determine the active power shortage of the gateway according to the target power and a preset gateway maintenance threshold; wherein the first target inverter is any inverter participating in the power-limited operation in the inverter system; The active power setting value of the energy storage system at the next moment is determined according to the active power setting value of the energy storage system at the current moment, the active power shortage of the gateway and the maximum power of the energy storage system, and the operating state of the energy storage system is adjusted according to the active power setting value of the energy storage system at the next moment.

3. The energy control method of a photovoltaic load storage microgrid according to claim 1 is characterized in that: The regulating the energy storage system and the inverter system according to the reverse power control threshold and the target power includes: The over-limit power value of the gateway is determined according to the target power and a preset reverse power maintenance threshold, and the energy storage system and the inverter system are regulated according to the over-limit power value of the gateway.

4. The energy control method of a photovoltaic load storage microgrid according to claim 3 is characterized in that: The regulating the energy storage system and the inverter system according to the over-limit power value of the gateway includes: If only the energy storage system participates in the limited power operation, the active power setting value of the energy storage system at the next moment is determined according to the active power setting value of the energy storage system at the current moment, the over-limit power value of the threshold and the minimum power value of the energy storage system, and the operating state of the energy storage system is adjusted according to the active power setting value of the energy storage system at the next moment; If only the inverter system participates in the power-limited operation, the actual active power value of the inverter system at the current moment is adjusted according to the priority of each inverter in the inverter system until the actual active power value of the inverter system at the current moment meets the over-limit power value of the threshold; Determine the active setting value of the second target inverter at the next moment according to the active actual value of the second target inverter at the current moment and the active adjustment value of the second target inverter, and adjust the operation state of the second target inverter according to the active setting value of the second target inverter at the next moment; wherein the second target inverter is any inverter participating in the limited power operation in the inverter system; the active adjustment value of the second target inverter is a pre-set power value; If both the energy storage system and the inverter system participate in power-limited operation, the active power setting value of the energy storage system at the next moment is determined according to the active power setting value of the energy storage system at the current moment, the over-limit power value of the threshold and the minimum power value of the energy storage system, and the operating state of the energy storage system is adjusted according to the active power setting value of the energy storage system at the next moment; Determine the remaining power shortage of the gateway according to the active power setting value of the energy storage system at the current moment, the active power setting value of the energy storage system at the next moment and the over-limit power value of the gateway, and adjust the active power actual value of each inverter in the inverter system according to the remaining power shortage of the gateway and the priority of each inverter in the inverter system until the active power actual value of the inverter system at the current moment meets the remaining power shortage of the gateway; Determine the active setting value of the third target inverter at the next moment according to the actual active value of the third target inverter at the current moment and the active adjustment value of the third target inverter, and adjust the operating state of the third target inverter according to the active setting value of the third target inverter at the next moment; wherein, the third target inverter is any inverter participating in power adjustment in the inverter system; the active adjustment value of the third target inverter is a pre-set power value.

5. The energy control method of a photovoltaic load storage microgrid according to claim 1 is characterized in that: The energy storage system and the inverter system are regulated based on the principle of minimizing the electricity cost and maximizing the output power of the inverter system, including: If the power grid is in a valley period or a deep valley period, charging the energy storage system; Determine the active setting value of the energy storage system at the next moment according to the active setting value of the energy storage system at the current moment, the target power, the target setting value, the upper and lower power limits of the energy storage system, and the preset reverse power maintenance threshold and the gate maintenance threshold; wherein the target setting value is set according to the actual operation requirements of the photovoltaic load-storage microgrid; If the power grid is in a peak period or a spike period, the active power shortage of the gateway is determined according to the target power and the gateway maintenance threshold, and the active power setting value of the energy storage system at the next moment is determined according to the active power shortage of the gateway; If the power grid is in a normal period, determining whether there is a peak period and / or a spike period after the normal period of the power grid; If not present, determining the active power setting value of the energy storage system at the next moment according to the reverse power maintenance threshold; If so, the step of determining the active power setting value of the energy storage system at the next moment according to the active power setting value of the energy storage system at the current moment, the target power, the target setting value, the upper and lower power limits of the energy storage system, and the preset reverse power maintenance threshold and the gate maintenance threshold is executed; Based on the principle of maximizing the power output of the inverter system, the active power setting value of the inverter system at the next moment is determined according to the active power setting value of the energy storage system at the current moment, the active power setting value of the energy storage system at the next moment, and the power supply demand of the load, and the active power setting value of the energy storage system at the next moment is re-determined according to the active power setting value of the energy storage system at the current moment and the active power setting value of the energy storage system at the next moment; The operating state of the inverter system is adjusted according to the active power setting value of the inverter system at the next moment, and the operating state of the energy storage system is adjusted according to the active power setting value of the energy storage system at the next moment.

6. The energy control method of a photovoltaic load storage microgrid according to claim 5 is characterized in that: Determining the active power setting value of the energy storage system at the next moment according to the active power setting value of the energy storage system at the current moment, the target power, the target setting value, the upper and lower power limits of the energy storage system, and the preset reverse power maintenance threshold and the gate maintenance threshold includes: Determine the reverse power control value of the energy storage system at the next moment according to the active power setting value of the energy storage system at the current moment, the target power, the active power setting value, the reverse power maintenance threshold value and the minimum power value of the energy storage system; Determine a threshold demand control value of the energy storage system at the next moment according to the active power setting value of the energy storage system at the current moment, the target power, the threshold maintenance threshold, the active power setting value and the maximum power of the energy storage system; If the reverse power control value of the energy storage system at the next moment is equal to the threshold demand control value of the energy storage system at the next moment, then determining the active power setting value of the energy storage system at the next moment according to the active power setting value; If the reverse power control value of the energy storage system at the next moment is not equal to the active power setting value, determining the active power setting value of the energy storage system at the next moment according to the reverse power control value of the energy storage system at the next moment; If the threshold demand control value of the energy storage system at the next moment is not equal to the active power setting value, the active power setting value of the energy storage system at the next moment is determined according to the threshold demand control value of the energy storage system at the next moment.

7. The energy control method of a photovoltaic load storage microgrid according to claim 5 is characterized in that: The principle of maximizing the power output of the inverter system is to determine the active setting value of the inverter system at the next moment according to the active setting value of the energy storage system at the current moment, the active setting value of the energy storage system at the next moment and the power supply demand of the load, and at the same time, re-determine the active setting value of the energy storage system at the next moment according to the active setting value of the energy storage system at the current moment and the active setting value of the energy storage system at the next moment, including: Determining whether there is an inverter in the inverter system that operates with limited power; If there is an inverter in limited power operation in the inverter system, an inverter that meets a first preset condition is selected from the inverters in limited power operation to obtain a first selected inverter, and the first selected inverter is controlled to be in an MPPT operation mode; wherein the actual active power value of the first selected inverter at the current moment is less than zero, or the active power setting value of the first selected inverter at the current moment is greater than or equal to zero, and the difference between the active power setting value of the first selected inverter at the current moment and the actual active power value of the first selected inverter at the current moment is greater than or equal to a preset value; Determining whether all inverters in the inverter system are in the MPPT operation mode; If yes, adjusting the operating state of the energy storage system according to the active power setting value of the energy storage system at the next moment; If not, then select an inverter that meets the second preset condition from the inverters in power-limited operation to obtain a target set, and determine the power adjustment value of the energy storage system according to the active power setting value of the energy storage system at the next moment and the active power setting value of the energy storage system at the current moment; wherein the second selected inverter is any inverter in the target set; the active power setting value of the second selected inverter at the current moment is greater than or equal to zero, and the difference between the active power setting value of the second selected inverter at the current moment and the active power actual value of the second selected inverter at the current moment is less than the preset value; Calculating a difference between the target power and the reverse power maintenance threshold to obtain a target difference; When the power adjustment value of the energy storage system is greater than zero; If the target difference is greater than zero, determining the active power shortage of the gateway according to the target power, the reverse power maintenance threshold and the power adjustment value of the energy storage system; If the target difference is less than or equal to zero, setting the active power deficit of the gateway to zero; Determining the active power setting value of the second screening inverter at the next moment according to the active power shortage of the gateway and the active actual value of each inverter in the target set at the current moment; When the power adjustment value of the energy storage system is less than zero; If the target difference is greater than zero, determining the active power shortage of the gateway according to the target power, the reverse power maintenance threshold and the power adjustment value of the energy storage system; If the target difference is less than or equal to zero, determining the active power deficit of the gateway according to the power adjustment value of the energy storage system; Determining the active power setting value of the second screening inverter at the next moment according to the active power shortage of the gateway, the actual active power value of each inverter in the target set at the current moment, and the rated active power of the inverter; When the power adjustment value of the energy storage system is equal to zero; Determine the active power deficit of the gateway according to the target power and the reverse power maintenance threshold, and determine the active power setting value of the second screening inverter at the next moment according to the active power deficit of the gateway, the actual active power value of each inverter in the target set at the current moment, and the rated active power of the inverter; The active power setting value of the energy storage system at the next moment is re-determined according to the power adjustment value of the energy storage system, the active power setting value of the energy storage system at the current moment and the active power setting value of the energy storage system at the next moment.

8. An energy control device for a photovoltaic load storage microgrid, characterized in that: include: The power detection module is used to detect the active power of the gateway in the photovoltaic load storage microgrid at the current moment and obtain the target power; The photovoltaic load-storage microgrid comprises: an inverter system, an energy storage system, a load and the gateway; A first control module is used to control the energy storage system and the inverter system based on the principle of minimizing the electricity cost and maximizing the output power of the inverter system if the target power is greater than or equal to the reverse power control threshold and less than the demand control threshold; the reverse power control threshold and the demand control threshold are set according to the grid connection requirements and user requirements of the power grid respectively; A second control module is used for, if the target power is greater than or equal to the demand control threshold, to maximize the output power of the inverter system and to control the inverter system and the energy storage system according to the power supply requirement of the load; The third control module is used to control the energy storage system and the inverter system according to the reverse power control threshold and the target power if the target power is less than the reverse power control threshold.

9. An electronic device, characterized in that: include: Memory for storing computer programs; A processor, configured to implement the steps of an energy control method for a photovoltaic load-storage microgrid as described in any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the energy control method of a photovoltaic load-storage microgrid as described in any one of claims 1 to 7 are implemented.

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