Energy storage and power grid coordination control system based on photovoltaic priority energy supply

Abstract

The invention discloses an energy storage and power grid coordination control system based on photovoltaic preferential energy supply, and relates to the technical field of power system dispatching automation, and the method comprises the steps: collecting the output power of a photovoltaic module, the charge state value of an energy storage unit and a load power demand in real time; dynamically calculating a photovoltaic and energy storage power distribution weight based on a preset photovoltaic priority energy supply strategy, and determining target output power of a photovoltaic module and an energy storage unit; when photovoltaic and energy storage cannot meet load requirements, power grid access control is automatically judged and triggered, so that continuity and stability of power supply are guaranteed. The problems that in the prior art, in the power dispatching process of an optical storage integrated system, dynamic reflection of the photovoltaic priority energy supply principle is lacked, the power distribution mode is not flexible, the power grid access response lags behind, and self-adaptive adjustment of dynamically adjusting the output current according to the real-time operation state is lacked are solved.

Description

Technical Field

[0001] This application relates to the technical field of power system dispatching automation, and particularly to a coordinated control system for energy storage and power grid based on photovoltaic (PV) priority energy supply. Background Art

[0002] With the large-scale access of renewable energy, PV power generation has become one of the important clean energy forms in the power system. However, due to the volatility and intermittency of PV power generation itself, it is difficult to stably match the real-time power demand of user loads. Usually, an energy storage system is needed to achieve dynamic balance and regulation of energy, so as to build an integrated energy supply system of PV and energy storage to improve the utilization efficiency of PV energy and the stability of system operation. In scenarios such as the user side and microgrids, the coordinated operation of PV and energy storage places higher requirements on the power distribution strategy. Especially when both have the ability to supply power, how to preferentially use PV resources and reasonably control the response of energy storage is a key factor affecting system efficiency and energy storage life.

[0003] Most of the existing dispatching methods for PV and energy storage systems adopt fixed priority or simple threshold judgment strategies for power distribution, lacking the joint evaluation of the real-time output capacity of PV and the current state of charge (SOC) value of energy storage, and unable to fully reflect the principle of PV priority energy supply. For example, when PV has a strong output capacity, some systems still frequently call the energy storage unit to discharge, which not only fails to maximize the utilization of clean energy but also accelerates the charge and discharge cycles of the energy storage device, affecting its service life. At the same time, traditional solutions usually do not set a dynamic weight distribution mechanism in multi-path energy supply scenarios and cannot intelligently calculate the target outputs of PV and energy storage according to the current power capabilities, resulting in unstable and uneconomical energy supply schemes.

[0004] Therefore, there is an urgent need to propose a coordinated control method and device for energy storage and power grid based on the PV priority energy supply strategy. This method can dynamically judge the feasibility of current energy supply paths according to information such as PV real-time power, energy storage SOC value, and load power demand, and realize the intelligent distribution of target power output by calculating the weight coefficients of PV and energy storage. On the premise of meeting the reliability of load energy supply, it preferentially uses PV resources, reasonably schedules the energy storage unit, and connects to the power grid for energy supplementation according to actual needs, so as to improve the overall energy efficiency and operation life of the PV and energy storage system. Summary of the Invention

[0005] The purpose of this application is to provide a coordinated control system for energy storage and power grid based on PV priority energy supply, which is used to solve the problems in the prior art that the integrated PV and energy storage system lacks dynamic reflection of the PV priority energy supply principle in the power dispatching process, the power distribution method is not flexible, the grid access response lags, and there is no adaptive regulation for dynamically adjusting the output current according to the real-time operation state.

[0006] In view of the above technical problems, the present application provides a coordinated control system for energy storage and power grid based on photovoltaic priority power supply.

[0007] In the first aspect of the embodiments of the present application, a coordinated control system for energy storage and power grid based on photovoltaic priority power supply is provided. The system includes: A data acquisition module, which is used to monitor the real-time photovoltaic power of photovoltaic modules in real time through a photovoltaic inverter, obtain the state of charge value of the energy storage unit through a battery management system, and the state of charge value is used to indicate the percentage of the current energy storage unit's power in its rated capacity, and monitor the load power demand on the load side in real time through a current sensor and a voltage sensor; A power distribution calculation module, which is used to dynamically calculate the photovoltaic power weight coefficient and the energy storage power weight coefficient based on a preset photovoltaic priority power supply strategy, using the collected photovoltaic real-time power, state of charge value and load power demand, to obtain the target output power of the photovoltaic module and the target charge and discharge power of the energy storage unit as the current power distribution plan; A dynamic power adjustment module, which is used to dynamically adjust the target output power of the photovoltaic module and the target charge and discharge power of the energy storage unit according to the real-time change of the load power demand, and optimize the power distribution path based on the current supply and demand state to obtain a corrected power distribution plan, and the power distribution path is used to indicate the power supply priority and power distribution ratio of the photovoltaic module and the energy storage unit to supply power to the load; A coordinated output module, which is used to generate a coordinated output control instruction including the control parameters of the target output power of the photovoltaic module and the control parameters of the target charge and discharge power of the energy storage unit according to the corrected power distribution plan, and send it to the photovoltaic module and the energy storage unit to coordinate the execution of the combined power output that conforms to the corrected power distribution plan; A power grid access module, which is used to generate a power grid access instruction for controlling the power grid to be connected if the photovoltaic real-time power is lower than the load power demand and the state of charge value is lower than the set threshold, and send the access instruction to the power grid used to trigger the power supply behavior of the power grid.

[0008] One or more technical solutions provided in the present application have at least the following technical effects or advantages: The real-time photovoltaic power of the photovoltaic modules is monitored through a photovoltaic inverter, the state of charge value of the energy storage unit is obtained through a battery management system, and the state of charge value is used to indicate the percentage of the current energy storage unit's power to its rated capacity. In addition, the load power demand on the load side is monitored in real time through a current sensor and a voltage sensor. Based on a preset photovoltaic priority energy supply strategy, the collected real-time photovoltaic power, state of charge value, and load power demand are used to dynamically calculate the photovoltaic power weight coefficient and the energy storage power weight coefficient, and obtain the target output power of the photovoltaic modules and the target charge and discharge power of the energy storage unit as the current power distribution plan. According to the real-time change of the load power demand, the target output power of the photovoltaic modules and the target charge and discharge power of the energy storage unit are dynamically adjusted, and the power distribution path is optimized based on the current supply and demand state to obtain a corrected power distribution plan. The power distribution path is used to indicate the power supply priority and power distribution ratio of the photovoltaic modules and the energy storage unit to supply power to the load. According to the corrected power distribution plan, a coordinated output control instruction including the control parameters of the target output power of the photovoltaic modules and the control parameters of the target charge and discharge power of the energy storage unit is generated and sent to the photovoltaic modules and the energy storage unit to coordinate the execution of the combined power output that conforms to the corrected power distribution plan. If the real-time photovoltaic power is lower than the load power demand and the state of charge value is lower than the set threshold, a grid access instruction for controlling the grid connection is generated and sent to the grid for triggering the grid energy supply behavior. This solves the problems in the prior art that the integrated photovoltaic and energy storage system lacks the dynamic embodiment of the photovoltaic priority energy supply principle, the power distribution method is not flexible, the grid access response is lagged, and there is no adaptive adjustment for dynamically adjusting the output current according to the real-time operating state.

[0009] The above description is only an overview of the technical solution of the present application. In order to be able to more clearly clarify the technical means of the present application, it can be implemented according to the content of the specification. Moreover, in order to make the above and other purposes, features, and advantages of the present application more obvious and understandable, the specific embodiments of the present application are given below. Brief Description of the Drawings

[0010] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments of the present disclosure will be briefly introduced below. Flowcharts are used in the present application to illustrate the operations performed by the system according to the embodiments of the present application. It should be understood that the operations in the front or below do not necessarily need to be executed precisely in sequence. On the contrary, according to the need, they can be executed in reverse order or simultaneously. At the same time, other operations can also be added to these processes, or one or several operations can be removed from these processes.

[0011] Figure 1 It is a schematic structural diagram of a coordinated control system for energy storage and grid based on photovoltaic priority energy supply provided by an embodiment of the present application; Description of the accompanying drawings: data acquisition module 10, power allocation calculation module 20, dynamic power adjustment module 30, coordination output module 40, grid access module 50. DETAILED DESCRIPTION

[0012] The present application provides a storage and grid coordination control system based on photovoltaic priority energy supply, which solves the problems in the prior art that the photovoltaic storage integrated system lacks dynamic embodiment of the photovoltaic priority energy supply principle in the power scheduling process, the power allocation method is inflexible, the grid access response is delayed, and there is a lack of adaptive regulation that dynamically adjusts the output current according to the real-time operating status.

[0013] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0014] It should be noted that the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or server that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or modules that are not explicitly listed or are inherent to these processes, methods, products or devices.

[0015] Embodiment 1, as Figure 1 As shown, the present application provides a storage and grid coordination control system based on photovoltaic priority energy supply, wherein the system includes: The data acquisition module 10 is used to monitor the real-time photovoltaic power of the photovoltaic module through the photovoltaic inverter, obtain the charge state value of the energy storage unit through the battery management system, and the charge state value is used to indicate the percentage of the current power of the energy storage unit to its rated capacity, and monitor the load power demand on the load side in real time through the current sensor and the voltage sensor.

[0016] Specifically, the system monitors the real-time photovoltaic power of photovoltaic modules through photovoltaic inverters, obtains the current state of charge (SOC) of the energy storage unit through the battery management system (BMS), and obtains the instantaneous power demand on the load side through the current sensor and voltage sensor installed on the load branch. The above three parameters are used as the basic input data for energy management scheduling, and the collection frequency is set according to the real-time requirements of the system to ensure the timeliness and accuracy of the power allocation response.

[0017] The power distribution calculation module 20 is configured to dynamically calculate the photovoltaic power weight coefficient and the energy storage power weight coefficient based on a preset photovoltaic priority energy supply strategy, using the collected real-time photovoltaic power, state of charge value, and load power demand, and obtain the target output power of the photovoltaic module and the target charge and discharge power of the energy storage unit as the current power distribution scheme.

[0018] Specifically, to implement the power allocation strategy based on photovoltaic priority energy supply, the system first collects the output power of the current photovoltaic module, the state of charge value (i.e., SOC) of the energy storage unit, and the power demand on the load side as input data. The system makes judgments and controls according to the preset photovoltaic priority energy supply rules: when the current output power of the photovoltaic module is greater than or equal to the load power demand, the system considers that the photovoltaic has the main supply ability, so the distribution weight of the photovoltaic power is set to 1 and the distribution weight of the energy storage power is set to 0. At this time, all loads are borne by the photovoltaic power supply; when the photovoltaic output is insufficient and the state of charge value of the energy storage unit is higher than the minimum discharge threshold set by the system, the system considers that the energy storage has the discharge ability. At this time, the photovoltaic weight is set to 0 and the energy storage weight is set to 1, and the load power is provided by the energy storage; when the photovoltaic output is not enough to independently meet the load but is still higher than the set minimum effective output threshold, and at the same time the state of charge value of the energy storage is also higher than the minimum discharge threshold, it means that both the photovoltaic and the energy storage can participate in power supply. The system will further estimate the dischargeable power of the energy storage unit, which is based on the rated capacity of the energy storage unit, battery voltage, current state of charge value, discharge efficiency, and discharge safety threshold. After obtaining the real-time output power of the photovoltaic and the dischargeable power of the energy storage, the system calculates the energy supply weights of the photovoltaic and the energy storage respectively according to the available power ratio of the two, and uses this as the basis for power distribution to ensure photovoltaic priority. The calculated weights will be used to further determine the target output power of the photovoltaic module and the target output power of the energy storage unit in the current cycle, forming a complete power distribution scheme. The advantage of this method is that it can dynamically adjust the power supply ratio of the photovoltaic and the energy storage in real time, maximize the utilization rate of photovoltaic resources while ensuring the stable power supply of the system, reduce the frequent charge and discharge behavior of the energy storage, help extend the life of the energy storage, and improve the overall energy efficiency of the system.

[0019] Further, the method of dynamically calculating the photovoltaic power weight coefficient and the energy storage power weight coefficient based on a preset photovoltaic priority energy supply strategy, using the collected real-time photovoltaic power, state of charge value, and load power demand, and obtaining the target output power of the photovoltaic module and the target charge and discharge power of the energy storage unit as the current power distribution scheme includes: Based on a preset photovoltaic priority energy supply strategy, obtain the photovoltaic power weight coefficient and the energy storage power weight coefficient for power distribution, and combine the currently collected load power demand to calculate the target output power of the photovoltaic module and the target charge and discharge power of the energy storage unit respectively. The calculation formulas are as follows: The formula for the target output power of the photovoltaic module is: = × ; Wherein is the load power demand, is the photovoltaic power weight coefficient, is the target output power of the photovoltaic module; The formula for the target charge-discharge power of the energy storage unit is: = × ; Wherein is the load power demand, is the energy storage power weight coefficient, is the target charge-discharge power of the energy storage unit, a positive value indicates discharge, and a negative value indicates charge.

[0020] Furthermore, the preset photovoltaic priority power supply strategy includes: If the real-time photovoltaic power is not less than the load power demand, it is determined that the photovoltaic module has the main power supply capacity, and the photovoltaic power weight coefficient = 1, the energy storage power weight coefficient = 0, and at this time, the output power of the energy storage unit is not determined at all; If the real-time photovoltaic power is lower than the load power demand, and if the state of charge value is not lower than the energy storage discharge lower limit threshold set by the system, it is determined that the energy storage unit has the discharge capacity, and the photovoltaic power weight coefficient = 0, the energy storage power weight coefficient = 1; If the real-time photovoltaic power is not less than the set minimum effective output threshold of the photovoltaic, and the state of charge value is not lower than the energy storage discharge lower limit threshold, and the dischargeable power calculated based on the current state of charge value, battery rated capacity, battery rated voltage, and discharge efficiency is greater than zero, it is determined that the photovoltaic module has the main power supply capacity and the energy storage unit has the discharge capacity; The calculation formula is as follows: ； ； Wherein, is the real-time photovoltaic power, is the estimated dischargeable power of the energy storage unit, is the photovoltaic power weight coefficient, is the energy storage power weight coefficient, satisfying + = 1; When increases, the increases accordingly, and the decreases accordingly, so as to preferentially allocate power to the output of the photovoltaic module; The calculation method of the estimated dischargeable power of the energy storage unit is: ； where is the rated capacity of the battery, is the rated voltage of the battery, is the state of charge value of the current energy storage unit, is the lower limit of the state of charge threshold range, is the discharge efficiency of the battery, is the estimated dischargeable power of the energy storage unit; The rated capacity of the battery is the device parameter preset in the system configuration, read and stored during the system deployment phase. The rated voltage of the battery is the nominal value provided by the battery manufacturer at the time of factory shipment. The discharge efficiency of the battery is preset by the system according to the model and characteristics of the selected energy storage unit.

[0021] Specifically, to implement the power scheduling strategy based on photovoltaic (PV) priority power supply, the system first collects the current real-time PV power, the state of charge (SOC) value of the energy storage unit, and the power demand of the current load, and dynamically calculates the PV power weight coefficient and the energy storage power weight coefficient based on these, so as to obtain the target output power of the PV modules and the target charge / discharge power of the energy storage unit. The system first assigns the power supply responsibility according to a set of preset PV priority judgment logics: when the real-time PV power is greater than or equal to the load power demand, the system determines that the PV modules have the ability to supply power independently as the main power source. At this time, the PV power weight is set to 1 and the energy storage power weight is set to 0, and the PV modules directly supply power in full; if the real-time PV power is insufficient to meet the load, but the SOC value of the energy storage unit is higher than the set minimum discharge threshold, the system determines that the energy storage has the ability to discharge, sets the energy storage weight to 1 and the PV weight to 0, and the power is completely provided by the energy storage; if the PV output is insufficient but still higher than the minimum effective output threshold, and the energy storage also has the ability to discharge (that is, the SOC value is higher than the threshold and the estimated dischargeable power is greater than 0), then the system determines that both the PV and the energy storage can supply power. At this time, by calculating the weighted ratio of the real-time PV power and the estimated dischargeable power of the energy storage, the power supply weight coefficients of the PV and the energy storage are obtained. Among them, the dischargeable power of the energy storage unit is estimated based on parameters such as the rated capacity, voltage, current SOC value, minimum discharge threshold, and discharge efficiency of the battery. Finally, the system multiplies the calculated PV power weight coefficient by the load power demand to obtain the target output power of the PV modules, and at the same time multiplies the energy storage weight coefficient by the load power demand to obtain the target power of the energy storage unit (a positive value indicates discharge, and a negative value indicates charge). The above process can ensure that PV power is preferentially utilized on the premise of meeting the load, while reasonably scheduling the energy storage resources, improving the PV utilization efficiency, extending the energy storage life, and ensuring the overall power supply stability and economy of the system.

[0022] The dynamic power adjustment module 30 is used to dynamically adjust the target output power of the PV modules and the target charge / discharge power of the energy storage unit according to the real-time change of the load power demand, and optimize the power distribution path based on the current supply and demand state to obtain a corrected power distribution plan. The power distribution path is used to indicate the power supply priority and power distribution ratio of the PV modules and the energy storage unit to supply power to the load; Further, it includes: Calculate the average value of the load power demand in the current scheduling period, and take the difference from the average value of the load power demand in the previous scheduling period to obtain the load power change value; When the load power demand increases, that is, the load power change value is positive, and the real-time PV power is less than the PV maximum output power threshold set by the system, it is determined that the PV module has remaining power generation capacity. According to the minimum value between the load power change value and the remaining power generation capacity, the target output power of the PV module is increased, and the energy storage unit maintains its current output state; When the load power change value is positive, and the real-time PV power output has reached the PV maximum output power threshold set by the system, and the state of charge value of the energy storage unit is higher than the discharge lower limit threshold set by the system, and the estimated discharge power of the energy storage unit is greater than zero, then the discharge part of the target charge-discharge power of the energy storage unit is increased to make up the load power difference; When the load power demand decreases, that is, the load power change value is negative, then the discharge part of the target charge-discharge power of the energy storage unit is decreased to avoid over-discharge, while maintaining the stable output of the PV module; Based on the available output power of the PV module and the discharge capacity of the energy storage unit, combined with the current load power demand, the priorities of the PV power supply path and the energy storage power supply path are judged, and the main power supply path is dynamically switched to realize the adjustment of the power distribution path and the reconstruction of the energy flow direction. The available output power of the PV module is the maximum output power calculated based on the current light intensity and the maximum output power limit set by the system. The discharge capacity of the energy storage unit is the maximum discharge power that can be released to the load when its state of charge value is higher than the discharge lower limit threshold set by the system; The target output power of the PV module and the target charge-discharge power of the energy storage unit after dynamic adjustment form a corrected power distribution scheme.

[0023] Specifically, to achieve adaptive regulation of energy distribution, the system dynamically adjusts the calculated target output power of the photovoltaic modules and the target charge-discharge power of the energy storage unit according to the real-time changing load power demand. On this basis, it optimizes the power distribution path based on the current supply-demand status, thereby forming a corrected power distribution plan. Among them, the power distribution path indicates the priority relationship between the photovoltaic modules and the energy storage unit during power supply and their corresponding power distribution ratios. Specifically, the system first calculates the average value of the load power demand within the current scheduling period and takes the difference from the average value of the previous scheduling period to obtain the load power change value. If the load power change value is positive, that is, the load power demand is increasing and the current real-time photovoltaic power is less than the maximum output power threshold set by the system, it is considered that the photovoltaic modules have surplus power generation capacity. The system increases the target output power of the photovoltaic modules according to the smaller value between the load power change value and the surplus power generation capacity, and the energy storage unit maintains its existing output unchanged. If the load power change value is positive and the photovoltaic modules are operating at full load, and at the same time the state of charge value of the energy storage unit is higher than the discharge lower limit threshold and the dischargeable power is greater than zero, the system determines that the energy storage has the ability to supplement energy and increases the target discharge power of the energy storage unit to make up for the load power difference. If the load power change value is negative, that is, the load demand is decreasing, the system reduces the target discharge power of the energy storage unit to prevent over-discharge of the battery, while keeping the output of the photovoltaic modules stable. On this basis, the system comprehensively judges the availability and priority of the photovoltaic path and the energy storage path according to the maximum available output power of the photovoltaic modules under the current light conditions (determined jointly by the light intensity and the inverter limit) and the maximum dischargeable power of the energy storage unit at the current state of charge value (calculated only when the state of charge value is higher than the set lower limit threshold), dynamically selects the main power supply path, and realizes the reconstruction of the power distribution path and the optimization of the energy flow direction. Finally, the adjusted target output power of the photovoltaic modules and the target charge-discharge power of the energy storage unit form a corrected power distribution plan, which is used to guide the energy supply execution within the current scheduling period.

[0024] A coordinated output module 40, which is configured to generate a coordinated output control instruction including the control parameter of the target output power of the photovoltaic modules and the control parameter of the target charge-discharge power of the energy storage unit according to the corrected power distribution plan, and send it to the photovoltaic modules and the energy storage unit to coordinately execute the combined power output that conforms to the corrected power distribution plan.

[0025] Specifically, after the system obtains the corrected power distribution scheme, it uses the determined target output power of the photovoltaic modules and the target charge-discharge power of the energy storage unit as the control basis to generate a coordinated output control instruction that includes these two power control parameters. The target output power of the photovoltaic modules is calculated based on the product of the photovoltaic power weight coefficient and the current load power demand, while the target charge-discharge power of the energy storage unit is calculated based on the product of the energy storage power weight coefficient and the current load power demand. The calculation basis of the above two weight coefficients includes the currently collected operating state parameters such as the real-time photovoltaic power, the state of charge of the energy storage, the rated capacity of the battery, the rated voltage of the battery, and the discharge efficiency, ensuring the rationality and responsiveness of power distribution. The generated control instruction is sent to the photovoltaic output control end and the energy storage control execution end respectively through communication means, driving both to execute power output synchronously according to the corrected power distribution scheme, thereby realizing the joint response to the load power demand and improving the coordination of system operation and the reliability of power supply.

[0026] Further, it includes: Extract the target output power value of the photovoltaic modules from the corrected power distribution scheme and the target charge-discharge power value of the energy storage unit ; Set the target current correction coefficient of the photovoltaic modules that is dynamically adjusted according to the system operating state and the target current correction coefficient of the energy storage unit ; Obtain the current output voltage value on the photovoltaic module side by collecting the real-time detection value of the DC side voltage of the photovoltaic inverter , based on the target output power value of the photovoltaic modules and the current output voltage value on the photovoltaic module side , calculate the target output current , The calculation formula is: ; wherein, is the target current correction coefficient of the photovoltaic modules, and the value range is 0.8 to 1.2; Input the target output power value of the photovoltaic modules into the maximum power point tracking controller MPPT, dynamically adjust the target voltage value using the voltage perturbation method, and combine the target output current value , generate the control parameters of the photovoltaic inverter including the target voltage and target current, and use them as the control parameters for the target output power of the photovoltaic modules; Judge the target charge-discharge power value of the energy storage unit The positive and negative signs are used to determine the control mode of the current energy storage unit, and control parameters for the target charge-discharge power of the energy storage unit are generated based on the control mode. The control parameters for the target charge-discharge power of the energy storage unit include the target current after amplitude limiting processing, the safety threshold judgment result, and the output control mode; The control parameters of the target output power of the photovoltaic module and the control parameters of the target charge-discharge power of the energy storage unit are encapsulated into a coordinated output control instruction, and the coordinated output control instruction is used to adjust the output current of the photovoltaic inverter and control the charge-discharge state of the energy storage converter; Drive the photovoltaic inverter and the energy storage converter according to the coordinated output control instruction to perform coordinated execution of the combined power output that conforms to the corrected power distribution scheme.

[0027] Further, judging the target charge-discharge power value of the energy storage unit The positive and negative signs are used to determine the control mode of the current energy storage unit, and control parameters for the target charge-discharge power of the energy storage unit are generated based on the control mode, including: When the target charge-discharge power value of the energy storage unit > 0, it is determined that the power control mode is the discharge mode, and the target current calculation method is according to Calculate the target discharge current; When the target charge-discharge power value of the energy storage unit < 0, it is determined that the power control mode is the charging mode, and the target current calculation method is according to = - Calculate the target charge current; Where is the target current correction coefficient of the energy storage unit, and the value range is 0.85 to 1.15, is the battery voltage value of the energy storage unit, is the target discharge current, is the target charge current; In the discharge mode, if the target discharge current exceeds the maximum discharge current threshold, the target current is limited to the maximum discharge current threshold, and the safety threshold judgment result is set to the over-limit state. In the charging mode, if the target charge current is lower than the opposite of the maximum charge current threshold, the target current is limited to the opposite of the maximum charge current threshold, and the safety threshold judgment result is set to the over-limit state. If the target current is within the charge-discharge current threshold range, the target current is maintained at its original value, and the safety threshold judgment result is set to the normal state; When the target charge-discharge power value of the energy storage unit >= the power control mode switching threshold When the current state of charge value SOC is within the state of charge threshold range, the output control mode is set to the constant power control mode, and the energy storage converter is driven to operate at a fixed power; When the target charge and discharge power value < the power control mode switching threshold or when the current state of charge value SOC exceeds the state of charge threshold range, the output control mode is set to the constant current control mode, and the energy storage converter is driven to charge and discharge at a fixed current, where is the power control mode switching threshold, and its value range is 200W to 500W. The state of charge threshold range is set to 25% to 85%; The limited target current, the safety threshold judgment result, and the output control mode are encapsulated as the control parameters of the target charge and discharge power of the energy storage unit.

[0028] Furthermore, the photovoltaic module target current correction coefficient dynamically adjusted according to the system operation state and the energy storage unit target current correction coefficient , including: Collect the ambient temperature of the photovoltaic module as the input parameter of the photovoltaic module target current correction coefficient, and collect the state of charge value SOC of the energy storage unit as the input parameter of the energy storage unit target current correction coefficient; When the ambient temperature of the photovoltaic module is higher than the set temperature threshold, to prevent device overheating, the value of the photovoltaic module target current correction coefficient is automatically reduced to reduce the target output current. The temperature threshold range is 35°C to 45°C; When the current state of charge value SOC of the energy storage unit is lower than the minimum state of charge limit threshold or higher than the maximum state of charge limit threshold, the energy storage unit target current correction coefficient is automatically reduced to the safe operating value range to avoid overcharge and overdischarge. The minimum state of charge limit threshold is 15%, and the maximum state of charge limit threshold is set to 85%.

[0029] The grid connection module 50 is used to generate a grid connection instruction for controlling the grid connection if the real-time photovoltaic power is lower than the load power demand and the state of charge value is lower than the set threshold, and send the connection instruction to the grid for triggering the grid power supply behavior.

[0030] Furthermore, it includes: Calculate the current photovoltaic power gap based on the difference between the load power demand and the real-time photovoltaic power of the photovoltaic module; If the photovoltaic power gap is greater than zero and the current state of charge value SOC of the energy storage unit is lower than the lower limit of the state of charge threshold range, it is determined that the photovoltaic component does not have the main supply capacity and the energy storage unit does not have the discharge capacity, then the grid access instruction is triggered, and the grid access instruction includes a grid start flag and a connection duration parameter, and the duration is the time calculated according to the ratio of the load power demand to the photovoltaic power gap; The grid access instruction is sent to the grid to start grid power supply, where the grid power supply is used to compensate for the load power gap that cannot be met by photovoltaic and energy storage, thereby ensuring the stability of power supply; If it is determined that the real-time photovoltaic power is not less than the load power demand on the load side and the current state of charge value SOC of the energy storage unit is not lower than the upper limit of the state of charge threshold range, it is considered that the energy storage unit has recovered to a normal charging and discharging state, triggering a grid shutdown command to terminate the grid energy supply behavior.

[0031] Specifically, when the system detects that the real-time output power of the photovoltaic module is lower than the current load power demand, and the current state of charge value SOC of the energy storage unit is lower than the lower limit of the state of charge threshold range set by the system, it means that photovoltaics and energy storage cannot provide enough energy to maintain the normal operation of the load at this stage. In order to ensure the continuity and stability of the power supply system, the system generates a grid access control instruction based on the above detection results, which includes a grid start-up flag and access duration parameters. The instruction is sent to the power grid with power supply control function through control communication, which is used to trigger the access operation on the grid side, so that the grid can supplement the current power gap. Specifically, the system first determines the power supply based on the load power demand. Real-time output power of photovoltaic modules The difference between the current photovoltaic power gap and the current photovoltaic power gap is calculated as ΔP= - ; If ΔP>0, and the current state of charge value SOC< , that is, lower than the discharge safety threshold set by the system, the system regeneration energy supply capacity is determined to be insufficient, triggering the above-mentioned grid access instruction. The access duration parameter can be based on the photovoltaic power gap ΔP and the load power demand The system calculates the ratio of power consumption to ensure that the grid's energy replenishment behavior accurately matches the current supply and demand gap. Furthermore, the system continuously monitors the photovoltaic power and energy storage status. If the real-time output power of the photovoltaic module is not less than the load power demand, and the state of charge value SOC of the energy storage unit recovers to above the upper limit of the set threshold range, it is determined that the current renewable energy supply capacity has been restored, and the system generates a grid shutdown instruction, which is sent to the grid to terminate the grid access behavior, thereby returning to the green energy power supply path based on photovoltaics and energy storage. This solution can dynamically identify the supply and demand balance state, flexibly introduce the grid to ensure the reliability of the system operation, while avoiding unnecessary grid energy use and improving overall energy utilization efficiency.

[0032] In summary, the embodiments of the present application at least have the following technical effects: The photovoltaic real-time power of the photovoltaic module is monitored in real time through a photovoltaic inverter, the state of charge value of the energy storage unit is obtained through a battery management system, and the state of charge value is used to indicate the percentage of the current energy storage unit's power in its rated capacity, and the load power demand on the load side is monitored in real time through a current sensor and a voltage sensor; based on a preset photovoltaic priority energy supply strategy, using the collected photovoltaic real-time power, state of charge value, and load power demand, the photovoltaic power weight coefficient and the energy storage power weight coefficient are dynamically calculated to obtain the target output power of the photovoltaic module and the target charge and discharge power of the energy storage unit as the current power distribution plan; according to the real-time change of the load power demand, the target output power of the photovoltaic module and the target charge and discharge power of the energy storage unit are dynamically adjusted, and the power distribution path is optimized based on the current supply and demand state to obtain a corrected power distribution plan, and the power distribution path is used to indicate the power supply priority and power distribution ratio of the photovoltaic module and the energy storage unit to supply power to the load; according to the corrected power distribution plan, a coordinated output control instruction including the control parameter of the target output power of the photovoltaic module and the control parameter of the target charge and discharge power of the energy storage unit is generated and sent to the photovoltaic module and the energy storage unit to coordinate the execution of the combined power output that conforms to the corrected power distribution plan; if the photovoltaic real-time power is lower than the load power demand and the state of charge value is lower than the set threshold, a grid access instruction for controlling the grid connection is generated and the access instruction is sent to the grid for triggering the grid energy supply behavior.

[0033] It should be noted that the above sequence of the embodiments of the present application is only for description and does not represent the advantages and disadvantages of the embodiments. And the above specific embodiments of the present specification are described. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than in the embodiments and still achieve the desired results. Additionally, the processes depicted in the figures do not necessarily require the specific order or sequential order shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0034] The above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0035] This specification and the accompanying drawings are merely illustrative of the present application and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of the present application. Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the present application and its equivalent technologies, the present application is intended to include these changes and modifications.

Claims

1. A coordinated control system for energy storage and power grid based on photovoltaic priority power supply, characterized in that Including: A data acquisition module, which is used to monitor the real-time photovoltaic power of photovoltaic modules in real time through a photovoltaic inverter, obtain the state of charge value of an energy storage unit through a battery management system, where the state of charge value is used to indicate the percentage of the current energy storage unit's power in its rated capacity, and monitor the load power demand on the load side in real time through a current sensor and a voltage sensor; A power distribution calculation module, which is used to dynamically calculate the photovoltaic power weight coefficient and the energy storage power weight coefficient based on a preset photovoltaic priority energy supply strategy, using the collected photovoltaic real-time power, state of charge value, and load power demand, and obtain the target output power of the photovoltaic module and the target charge-discharge power of the energy storage unit as the current power distribution plan; A dynamic power adjustment module, which is used to dynamically adjust the target output power of the photovoltaic module and the target charge-discharge power of the energy storage unit according to the real-time change of the load power demand, and optimize the power distribution path based on the current supply and demand state to obtain a corrected power distribution plan, where the power distribution path is used to indicate the power supply priority and power distribution ratio of the photovoltaic module and the energy storage unit to supply power to the load; A coordinated output module, which is used to generate a coordinated output control instruction including the control parameters of the target output power of the photovoltaic module and the control parameters of the target charge-discharge power of the energy storage unit according to the corrected power distribution plan, and send it to the photovoltaic module and the energy storage unit to coordinate the execution of the combined power output that conforms to the corrected power distribution plan; A grid access module, which is used to generate a grid access instruction for controlling the grid connection if the photovoltaic real-time power is lower than the load power demand and the state of charge value is lower than the set threshold, and send the access instruction to the grid used to trigger the grid energy supply behavior.

2. The energy storage and power grid coordination control system based on photovoltaic priority power supply according to claim 1, wherein The method of dynamically calculating the photovoltaic power weight coefficient and the energy storage power weight coefficient based on a preset photovoltaic priority energy supply strategy, using the collected photovoltaic real-time power, state of charge value, and load power demand, and obtaining the target output power of the photovoltaic module and the target charge-discharge power of the energy storage unit as the current power distribution plan includes: Based on a preset photovoltaic priority energy supply strategy, obtain the photovoltaic power weight coefficient and the energy storage power weight coefficient for power distribution, and combine the currently collected load power demand to calculate the target output power of the photovoltaic module and the target charge-discharge power of the energy storage unit respectively. The calculation formulas are as follows: The formula for the target output power of the photovoltaic module is: = × ； wherein is the load power demand is the photovoltaic power weight coefficient is the target output power of the photovoltaic module The formula for the target charge-discharge power of the energy storage unit is: = × ； wherein is the load power demand, is the energy storage power weight coefficient, is the target charge-discharge power of the energy storage unit, where a positive value indicates discharge and a negative value indicates charge.

3. The energy storage and power grid coordination control system based on photovoltaic priority power supply according to claim 2, wherein, The preset photovoltaic priority energy supply strategy includes: If the real-time photovoltaic power is not less than the load power demand, it is determined that the photovoltaic module has the main power supply ability, and the photovoltaic power weight coefficient is set = 1, and the energy storage power weight coefficient = 0. At this time, the output power of the energy storage unit is not determined at all; If the real-time PV power is lower than the load power demand and if the state of charge value is not lower than the lower limit threshold of energy storage discharge set by the system, it is determined that the energy storage unit has the discharge capacity, and the PV power weight coefficient is set = 0, and the energy storage power weight coefficient = 1; If the photovoltaic real-time power is not less than the set minimum effective output threshold of the photovoltaic, and the state of charge value is not lower than the energy storage discharge lower limit threshold, and the dischargeable power calculated based on the current state of charge value, battery rated capacity, battery rated voltage, and discharge efficiency is greater than zero, then it is determined that the photovoltaic module has the main power supply ability and the energy storage unit has the discharge ability; The calculation formula is as follows: ； ； Among them, is the real-time PV power, is the estimated discharge power of the energy storage unit, is the PV power weight coefficient, is the energy storage power weight coefficient, satisfying + = 1; When increases, the increases correspondingly, and the decreases correspondingly, so as to preferentially allocate power to the output of the photovoltaic module; The calculation method for the estimated dischargeable power of the energy storage unit is: ； Among them, is the rated capacity of the battery, is the rated voltage of the battery, is the state of charge value of the current energy storage unit, is the lower limit of the state of charge threshold range, is the discharge efficiency of the battery, is the estimated dischargeable power of the energy storage unit; The rated capacity of the battery is a device parameter preset in the system configuration, which is read and stored during the system deployment phase. The rated voltage of the battery is the nominal value provided by the battery manufacturer at the time of factory shipment. The discharge efficiency of the battery is preset by the system according to the model and characteristics of the selected energy storage unit.

4. The energy storage and power grid coordinated control system based on photovoltaic priority power supply according to claim 3, wherein, According to the real-time change of the load power demand, dynamically adjust the target output power of the photovoltaic module and the target charge-discharge power of the energy storage unit, and optimize the power distribution path based on the current supply-demand state to obtain a corrected power distribution plan. The power distribution path is used to indicate the power supply priority and power distribution ratio of the photovoltaic module and the energy storage unit to supply power to the load, and includes: Calculate the average value of the load power demand within the current scheduling period, and perform a difference operation with the average value of the load power demand in the previous scheduling period to obtain the load power change value; When the load power demand increases, that is, the load power change value is positive, and the real-time power of the photovoltaic is less than the maximum output power threshold of the photovoltaic set by the system, it is determined that the photovoltaic module has remaining power generation capacity. According to the minimum value between the load power change value and the remaining power generation capacity, increase the target output power of the photovoltaic module, and the energy storage unit maintains the current output state; When the load power change value is positive, and the real-time power output of the photovoltaic has reached the maximum output power threshold of the photovoltaic set by the system, and the state of charge value of the energy storage unit is higher than the discharge lower limit threshold set by the system, and the estimated dischargeable power of the energy storage unit is greater than zero, increase the discharge part of the target charge-discharge power of the energy storage unit to make up the load power difference; When the load power demand decreases, that is, the load power change value is negative, decrease the discharge part of the target charge-discharge power of the energy storage unit to avoid over-discharge, and at the same time maintain the stable output of the photovoltaic module; Based on the available output power of the photovoltaic module and the dischargeable capacity of the energy storage unit, combined with the current load power demand, judge the priority of the photovoltaic power supply path and the energy storage power supply path, dynamically switch the main power supply path, and realize the adjustment of the power distribution path and the reconstruction of the energy flow direction. The available output power of the photovoltaic module is the maximum output power calculated based on the current light intensity and the maximum output power limit set by the system. The dischargeable capacity of the energy storage unit is the maximum discharge power that can be released to the load under the condition that its state of charge value is higher than the discharge lower limit threshold set by the system; Form a corrected power distribution plan with the dynamically adjusted target output power of the photovoltaic module and the target charge-discharge power of the energy storage unit.

5. The energy storage and power grid coordination control system based on photovoltaic priority power supply according to claim 1, wherein According to the corrected power distribution plan, generate a coordinated output control instruction including the control parameter of the target output power of the photovoltaic module and the control parameter of the target charge-discharge power of the energy storage unit, and send it to the photovoltaic module and the energy storage unit to coordinate and execute the combined power output that conforms to the corrected power distribution plan, including: Extract the target output power value of the photovoltaic module from the corrected power distribution scheme and the target charge-discharge power value of the energy storage unit ; Photovoltaic module target current correction factor dynamically adjusted according to the system operating state And the energy storage unit target current correction factor ; Obtain the current output voltage value of the photovoltaic module side by collecting the real-time detection value of the DC side voltage of the photovoltaic inverter , based on the target output power value of the photovoltaic module and the output voltage value of the current photovoltaic module side , calculate the target output current , The calculation formula is as follows: ; Among them, is the target current correction factor of the photovoltaic module, and its value range is 0.8 to 1.2; Input the target output power value of the photovoltaic module into the maximum power point tracking controller MPPT, dynamically adjust the target voltage value by using the voltage perturbation method, and combine the target output current value , generate the control parameters of the photovoltaic inverter including the target voltage and target current as the control parameters for the target output power of the photovoltaic module; Determine the positive and negative signs of the target charge-discharge power value of the energy storage unit to determine the control mode in which the current energy storage unit is located, and generate control parameters for the target charge-discharge power of the energy storage unit based on the control mode. The control parameters for the target charge-discharge power of the energy storage unit include the target current after amplitude limiting processing, the safety threshold judgment result, and the output control mode; Package the control parameter of the target output power of the photovoltaic module and the control parameter of the target charge-discharge power of the energy storage unit into a coordinated output control instruction. The coordinated output control instruction is used to adjust the output current of the photovoltaic inverter and control the charge-discharge state of the energy storage converter; Drive the photovoltaic inverter and the energy storage converter to perform coordinated joint power output in accordance with the corrected power distribution scheme according to the coordinated output control instruction.

6. The energy storage and power grid coordinated control system based on photovoltaic priority power supply according to claim 5, characterized in that, Judging the positive and negative signs of the target charge-discharge power value of the energy storage unit to determine the control mode in which the current energy storage unit is located, and generating control parameters for the target charge-discharge power of the energy storage unit based on the control mode, including: When the target charge-discharge power value of the energy storage unit > 0, determine that the power control mode is the discharge mode, and the target current calculation method is in accordance with Calculate the target discharge current; When the target charge-discharge power value of the energy storage unit < 0, determine that the power control mode is the charging mode, and the target current calculation method is in accordance with = - Calculate the target charging current; wherein is the correction coefficient of the target current of the energy storage unit, and its value range is 0.85 to 1.15, is the battery voltage value of the energy storage unit, is the target discharge current, is the target charge current; In the discharge mode, if the target discharge current exceeds the maximum discharge current threshold, limit the target current to the maximum discharge current threshold, and set the safety threshold judgment result to the over-limit state. In the charging mode, if the target charging current is lower than the opposite of the maximum charging current threshold, then limit the target current to the opposite of the maximum charging current threshold, and set the safety threshold judgment result to the over-limit state. If the target current is within the charge and discharge current threshold range, keep the target current at its original value, and set the safety threshold judgment result to the normal state; When the target charge-discharge power value of the energy storage unit >= the power control mode switching threshold and the current state of charge value SOC is within the state of charge threshold range, the output control mode is set to the constant power control mode, and the energy storage converter is driven to operate at a fixed power; When the target charge-discharge power value <the power control mode switching threshold or when the current state of charge (SOC) value exceeds the state of charge threshold range, the output control mode is set to the constant current control mode, and the energy storage converter is driven to charge and discharge at a fixed current, where is the power control mode switching threshold, with a value range of 200W to 500W, and the state of charge threshold range is set to 25% to 85%; Package the target current after amplitude limiting processing, the safety threshold judgment result, and the output control mode as control parameters for the target charge and discharge power of the energy storage unit.

7. A coordinated control system for energy storage and power grid based on photovoltaic priority power supply according to claim 5, characterized in that, The photovoltaic module target current correction factor dynamically adjusted according to the system operating state and the energy storage unit target current correction factor , including: Collect the ambient temperature of the photovoltaic module as an input parameter for the correction coefficient of the target current of the photovoltaic module, and collect the state of charge value SOC of the energy storage unit as an input parameter for the correction coefficient of the target current of the energy storage unit; When the ambient temperature of the photovoltaic module is higher than the set temperature threshold, to prevent device overheating, automatically reduce the value of the correction coefficient of the target current of the photovoltaic module to reduce the target output current, and the temperature threshold range is 35°C to 45°C; When the current state of charge value SOC of the energy storage unit is lower than the minimum state of charge limit threshold or higher than the maximum state of charge limit threshold, automatically correct the target current correction coefficient of the energy storage unit to a safe operating value range to avoid overcharging and over-discharging, where the minimum state of charge limit threshold is 15% and the maximum state of charge limit threshold is set to 85%.

8. A coordinated control system for energy storage and power grid based on photovoltaic priority power supply according to claim 1, characterized in that, If the real-time photovoltaic power is lower than the load power demand and the state of charge value is lower than the set threshold, generate a grid access instruction for controlling the grid connection, and send the access instruction to the grid for triggering the grid power supply behavior, including: Calculate the current photovoltaic power gap based on the difference between the load power demand and the real-time power of the photovoltaic module; If the photovoltaic power gap is greater than zero and the current state of charge value SOC of the energy storage unit is lower than the lower limit of the state of charge threshold range, it is determined that the photovoltaic module does not have the main power supply ability and the energy storage unit does not have the discharge ability, then trigger the grid access instruction, and the grid access instruction includes a grid opening identifier and an access duration parameter, and the duration is the time calculated according to the ratio of the load power demand to the photovoltaic power gap; Send the grid access instruction to the grid to start grid power supply, and the grid power supply behavior is used to compensate for the load power gap that cannot be satisfied by the photovoltaic and energy storage, to ensure power supply stability; Judge that if the real-time photovoltaic power is not less than the load power demand on the load side and the current state of charge value SOC of the energy storage unit is not lower than the upper limit of the state of charge threshold range, it is considered that the energy storage unit has recovered to the normal charge and discharge state, trigger the grid shutdown instruction, and terminate the grid power supply behavior.

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