Control method and device, storable medium and photovoltaic energy storage equipment

Abstract

The invention provides a control method and device, a storable medium and photovoltaic energy storage equipment, and relates to the technical field of photovoltaic energy storage. The control method comprises the following steps: acquiring the power of a power grid, the current battery electric quantity of a battery module and current time information; determining a current working mode of the photovoltaic energy storage equipment according to the current time information; based on the current working mode, determining target working power of the battery module according to the power of the power grid or the current battery electric quantity; based on the current working mode, controlling the photovoltaic energy storage equipment to execute target operation according to the target working power; wherein the target operation comprises the steps of charging the battery module and supplying power to the load through the battery module. According to the invention, the target working power of the battery module can be always matched with the actual working condition of the photovoltaic energy storage equipment, and the energy utilization rate of photovoltaic power generation is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic energy storage, in particular to a control method and device, a readable storage medium and a photovoltaic energy storage device. BACKGROUND

[0002] In the related art, a photovoltaic energy storage device can generate electricity through a photovoltaic device and store the electricity generated by the photovoltaic device. When the stored energy reaches a certain amount of electricity or power grid fluctuations occur, the battery module of the photovoltaic energy storage device can supply power to the load.

[0003] The battery module of the photovoltaic energy storage device can only charge and discharge at a fixed power preset, while the power generation of the photovoltaic device will fluctuate greatly depending on whether the sunlight is sufficient. This results in a mismatch between the battery power and the actual working condition of the photovoltaic energy storage device, resulting in low energy utilization. SUMMARY

[0004] The present application aims to at least solve one of the technical problems existing in the prior art or related art.

[0005] To this end, the first aspect of the present application provides a control method of a photovoltaic energy storage device.

[0006] The second aspect of the present application provides a control device of a photovoltaic energy storage device.

[0007] The third aspect of the present application provides a control device of a photovoltaic energy storage device.

[0008] The fourth aspect of the present application provides a readable storage medium.

[0009] The fifth aspect of the present application provides a photovoltaic energy storage device.

[0010] Therefore, the first aspect of the present application provides a control method of a photovoltaic energy storage device, the photovoltaic energy storage device being electrically connected to a power grid and a load, the photovoltaic energy storage device comprising a battery module, the control method comprising: obtaining power grid power, a current battery capacity of the battery module and current time information; determining a current working mode of the photovoltaic energy storage device according to the current time information; determining a target working power of the battery module according to the power grid power or the current battery capacity based on the current working mode; controlling the photovoltaic energy storage device to perform a target operation according to the target working power based on the current working mode; wherein the target operation comprises charging the battery module or supplying power to the load through the battery module.

[0011] In the technical solution, the photovoltaic energy storage device is electrically connected to the power grid and the load, and includes a battery module which can include a plurality of battery cells. The photovoltaic energy storage device also includes a photovoltaic (PV) power generation module. The photovoltaic energy storage device uses the phenomenon that a semiconductor and a metal combined part generates a voltage to directly convert the radiant energy of the sun into electric energy, thereby realizing photovoltaic power generation.

[0012] The electric energy generated by the photovoltaic power generation can be directly provided to the load for use, or can be charged to the battery module, so that the electric energy generated by the photovoltaic power generation is stored through the battery module. In the case where the conditions are suitable, the load is powered by the electric energy stored in the battery module, thereby reducing the amount of electricity taken from the power grid and reducing the electricity cost.

[0013] In some embodiments, the photovoltaic energy storage device can also realize grid connection, so as to deliver the surplus electric energy generated by the photovoltaic power generation to the power grid, realize power selling to the power grid, and thereby generate a profit, which can also indirectly reduce the electricity cost of the household.

[0014] In order to better utilize the electric energy generated by the photovoltaic power generation, how to reasonably allocate the charging and discharging power of the battery is an important key to the utilization rate of the photovoltaic power generation. At the same time, keeping the battery in a reasonable and healthy power range is also conducive to improving the battery life. At the same time, when the power grid appears temporary power failure and other fluctuation faults, sufficient power is reserved to temporarily power the load, thereby reducing the impact of power failure on electricity.

[0015] Therefore, the technical solution of the present application proposes a control method of a photovoltaic energy storage device. The method divides the working mode of the photovoltaic energy storage device based on time periods, such as charging time periods and non-charging time periods. The charging time period refers to a time period in which the charging of the battery is preferentially ensured. The charging time period can be selected as a time period in which the load is small and the electricity usage scenario is less, such as the daytime of weekdays. At this time, the household electricity consumption is small, but the illumination is generally sufficient. Therefore, these time periods can be used to preferentially charge the battery module and store the electric energy. The charging time period can also be selected as a time period in which the electricity price is in a trough. The photovoltaic energy storage device receives the electricity price trough time period issued by the power grid through a communication protocol, and preferentially charges the battery module in the electricity price trough time period. The non-charging time period can dynamically switch the charging and discharging modes of the battery according to the load, power generation capacity and other specific working conditions, thereby ensuring the utilization rate of photovoltaic energy.

[0016] Exemplarily, the photovoltaic energy storage device determines the current working mode of itself according to the obtained current time information, and selects to determine the target working power of the battery module according to the grid power or according to the real-time point battery power of the battery module at the current time point according to different working modes, the target working power being the power when the battery module charges or discharges.

[0017] Exemplarily, whether the battery module charges or supplies power to the load can be determined by the positive or negative value of the target working power. For example, assuming that the current direction in the photovoltaic energy storage device is the direction pointing to the AC busbar, the target working power is positive, and at this time, the battery module is in the discharging state. When the current direction in the photovoltaic energy storage device is the direction away from the AC busbar, the target working power is negative, and at this time, the battery module is in the charging state.

[0018] After the current working mode of the photovoltaic energy storage device and the target working power of the battery module in the current working mode are determined, the photovoltaic energy storage device automatically performs the corresponding target operation according to the current working mode and the target working power, wherein the target working power is the power on the grid side. Exemplarily, when the target working mode is the charging mode, the photovoltaic energy storage device charges the battery module with the target working power as the charging power. Exemplarily, when the target working mode is the non-charging mode and the target working power is positive, the battery module is controlled to supply power to the load with the target working power as the discharging power.

[0019] The technical scheme provided in the present application divides the working mode of the photovoltaic energy storage device based on the time period, and dynamically adjusts the charging power or discharging power of the battery module according to different working modes, so that the target working power of the battery module can always match the actual working condition of the photovoltaic energy storage device, and the energy utilization rate of photovoltaic power generation is improved.

[0020] In addition, the control method of the photovoltaic energy storage device in the above technical scheme provided in the present application can have the following additional technical features:

[0021] In some technical schemes of the present application, optionally, determining the current working mode of the photovoltaic energy storage device according to the current time information comprises: in the case that the current time information is in the charging time period, determining that the current working mode is the charging mode; or in the case that the current time information is outside the charging time period, determining that the current working mode is the non-charging mode.

[0022] In the technical solution, the time period in a natural day is divided into charging time period and non-charging time period in units of hours or minutes. The photovoltaic energy storage device can obtain current time information through networking or according to its own timer, and determine whether the current time information is in the charging time period or the non-charging time period.

[0023] If it is determined that the current time information is in the charging time period, it is determined that the current working mode of the photovoltaic energy storage device is the charging mode. If it is determined that the current time information is not in the charging time period, it is determined that the current working mode of the photovoltaic energy storage device is the non-charging mode.

[0024] For example, assuming that the time period from 11:00 to 15:00 in a day is set as the charging time period, and the current time information is 12:45, it is determined that the current working mode is the charging mode.

[0025] For example, assuming that the time period from 13:00 to 16:00 in a day is set as the charging time period, and the current time information is 19:00, it is determined that the current working mode is the non-charging mode.

[0026] It can be understood that the charging time period can be dynamically adjusted for weekdays and non-weekdays, holidays and non-holidays, different seasons, etc.

[0027] It can be understood that the user can freely set the charging time period through a control panel or other electronic device programs connected to the photovoltaic energy storage device.

[0028] The technical solution of the present application can improve the energy utilization rate of photovoltaic power generation by setting the charging time period to distinguish the working mode of the photovoltaic energy storage device.

[0029] In some technical solutions of the present application, optionally, based on the current working mode, the target working power of the battery module is determined according to the grid power or the current battery power, comprising: in the case that the current working mode is the charging mode, obtaining the charging configuration information of the photovoltaic energy storage device; in the case that the charging configuration information is to charge the battery module through the grid, and the current battery power is less than the maximum charging power of the battery module, determining a first working power according to the maximum charging power, the current battery power, the charging time period and the current time information; and determining the target working power according to the first working power.

[0030] In the technical solution, if it is determined that the current time information is in the charging time period, that is, the current working mode of the photovoltaic energy storage device is the charging mode, the charging configuration information is obtained, and the charging configuration information sets that the photovoltaic energy storage device can use the power of the grid to charge the battery module.

[0031] When the charging configuration information allows the battery module to be charged through the power grid, the photovoltaic energy storage device can simultaneously use the surplus power of the photovoltaic power generation module and the power supplied by the power grid to charge the battery module, thereby improving the charging speed, ensuring that the power of the battery module can always be maintained at a relatively high power level, and reducing the impact of power failure.

[0032] When the charging configuration information does not allow the battery module to be charged through the power grid, the photovoltaic energy storage device intelligently uses the surplus power of the photovoltaic power generation module to charge the battery module, thereby minimizing the consumption of power grid power and reducing electricity costs.

[0033] If it is determined that the current working mode of the photovoltaic energy storage device is the charging mode, and the charging configuration information allows charging through the power grid, it is determined whether the current battery power (State Of Charge, SOC) reaches the maximum charging power, which is the power threshold when charging the battery module. If the current battery power does not reach the maximum charging power, the first working power is determined according to the maximum charging power, the current battery power, the charging time period and the current time information.

[0034] Exemplarily, the first working power is calculated by the following formula (1):

[0035] Psmoothcharge = (SOCmax-SOC)÷(t2-t1); (1)

[0036] Wherein, Psmoothcharge is the first working power, SOCmax is the maximum charging power, SOC is the current battery power, t2 is the end time point of the charging time period, and t1 is the time point corresponding to the current time information.

[0037] It can be understood that the first working power here is the working power that fully utilizes the charging time period to smoothly charge the battery module to the maximum charging power. The target working power when charging the battery module is determined according to the first working power, which can smoothly charge the battery module. When the photovoltaic power generation surplus is insufficient, the battery module can be smoothly charged by taking power from the power grid.

[0038] The technical scheme of the present application can smoothly charge the battery module, so that the battery module can always be fully charged at the end of the charging time period, ensuring the battery charging efficiency.

[0039] In some technical solutions of the present application, optionally, based on the current working mode, the target working power of the battery module is determined according to the grid power or the current battery power, comprising: in the case that the current working mode is the charging mode, obtaining the charging configuration information of the photovoltaic energy storage device; in the case that the charging configuration information is that the battery module is charged by the grid, and the current battery power is greater than or equal to the maximum charging power of the battery module, or in the case that the charging configuration information is that the battery module is not charged by the grid, determining the first working power according to the grid power and the current working power of the battery module; determining the target working power according to the first working power.

[0040] In this technical solution, if the current working mode of the photovoltaic energy storage device is the charging mode, the charging configuration information allows charging by the grid, but the current battery power has reached or exceeded the maximum charging power, then the battery module will not charge, at this time the first working power is determined according to the current working power of the battery module and the grid power.

[0041] If it is determined that the current working mode of the photovoltaic energy storage device is the charging mode, and the charging configuration information does not allow charging by the grid, then at this time the photovoltaic energy storage device can only charge the battery module by the surplus power of the photovoltaic power generation module, it can be understood that the above-mentioned surplus power refers to the part of the power generated by the photovoltaic power generation module after the part of the power directly used for power supply to the load is removed, at this time the first working power is also determined according to the current working power of the battery module and the grid power.

[0042] Exemplarily, the first working power is calculated by the following formula (2):

[0043] PObjabt1 = Pbat + Pgrid; (2)

[0044] Wherein, PObjabt1 is the first working power, Pbat is the current working power, and Pgrid is the grid power.

[0045] Exemplarily, in the charging mode, the battery will not discharge externally, after the current battery power of the battery module reaches the maximum charging power, the battery module will not charge, at this time the charging power of the battery module, that is, the current working power is 0, and the grid power is the data obtained by the grid metering module, the grid power is negative when the grid is fed to the grid, and the grid power is positive when the grid is taken from the grid.

[0046] For the case that the current battery power reaches the maximum charging power, if the grid power is negative, the first working power is negative, the first working power being negative indicates that the battery module charges according to the working power, and since the battery module is full at this time, the actual target charging power is actually 0. If the grid power is positive, the first working power is also positive, the first working power being positive indicates that the battery module discharges according to the working power, and since it is in the charging mode at this time, the battery module will not discharge externally, so the actual target charging power is also 0.

[0047] For the case that the battery module is not allowed to be charged by grid power, if the grid power is negative, the first working power is negative, the first working power being negative indicates that the battery module charges according to the working power. If the grid power is positive, the first working power is positive, the first working power being positive indicates that the battery module discharges according to the working power, and since it is in the charging mode at this time, the battery module will not discharge externally, so the actual target charging power is 0.

[0048] The technical scheme of the present application can reasonably allocate the battery charging power according to the current battery power and whether the battery is allowed to be charged by the grid, thereby realizing full utilization of photovoltaic power and improving the energy utilization rate of photovoltaic power generation.

[0049] In some technical schemes of the present application, the target working power of the battery module is determined according to the grid power or the current battery power based on the current working mode, including: in the case that the current working mode is a non-charging mode, determining a first working power according to the grid power and the current working power of the battery module; determining the target working power according to the first working power.

[0050] In this technical scheme, if the current working mode of the photovoltaic energy storage device is a non-charging mode, the battery module can discharge externally to supply power to the load through the energy stored in the battery module when the condition is met, at this time, the first working power is determined according to the current working power of the battery module and the grid power. Exemplarily, the first working power is calculated by the above formula (2).

[0051] In the non-charging mode, the battery module can discharge externally, assuming that the battery module is in a discharging state, the current working power of the battery module is positive, and when the battery module is in a charging state, the current working power of the battery module is negative. Similarly, the grid power is negative when the photovoltaic energy storage device is connected to the grid to output power to the grid, and the grid power is positive when power is taken from the grid.

[0052] If the first working power is positive, the battery module is controlled to discharge according to the target working power determined finally; if the first working power is negative, the battery module is controlled to charge according to the target working power determined finally.

[0053] The technical scheme of the present application can dynamically adjust the target working power of the battery module for charging or discharging according to the grid power and the current working power of the battery module in the non-charging mode, and can effectively improve the energy utilization rate of photovoltaic power generation.

[0054] In some technical schemes of the present application, the target working power is determined according to the first working power, including: in the case that the first working power is less than or equal to the maximum working power of the battery module, the first working power is determined as the target working power; or in the case that the first working power is greater than the maximum working power of the battery module, the first threshold power is determined as the target working power.

[0055] In the technical scheme, the maximum working power of the battery module is the power threshold of the battery module when charging or discharging, and when the current working power of the battery module is greater than the maximum working power, the battery may be heated and other problems may occur, affecting the safety of power consumption.

[0056] Therefore, after the first working power is calculated, the greater one between the first working power and the maximum working power is taken as the target power of the battery.

[0057] For example, when the first working power is the charging power (negative value) and the absolute value of the first working power is greater than the charging power threshold of the battery module (the absolute value of the maximum working power), the maximum working power of the battery module is set as the target working power, that is, the battery module is charged by the maximum charging power.

[0058] For example, when the first working power is the discharging power (positive value) and the absolute value of the first working power is less than the discharging power threshold of the battery module (the absolute value of the maximum working power), the first working power is set as the target working power, that is, the battery module is controlled to supply power to the load by the first working power.

[0059] The technical scheme of the present application can select the greater one between the first working power and the maximum working power as the target working power, which can ensure the working safety of the battery module and improve the reliability of the photovoltaic energy storage device while ensuring the charging and discharging efficiency.

[0060] In some technical solutions of the present application, optionally, the current working mode includes a charging mode and a non-charging mode; based on the current working mode, the target operation of the photovoltaic energy storage device according to the target working power is controlled, including: in the case that the current working mode is the charging mode and the current battery power is less than the maximum charging power, the photovoltaic energy storage device is controlled to charge the battery module according to the target working power; or in the case that the current working mode is the non-charging mode and the current battery power is greater than the power threshold, the photovoltaic energy storage device is controlled to supply power to the load according to the target working power.

[0061] In this technical solution, in the charging mode, the photovoltaic energy storage device preferentially ensures the charging process of the battery module, at this time, if the current battery power has not reached the maximum charging power, that is, the battery module has not been fully charged, then the battery module is charged through the determined target working power, until the current battery power of the battery module is greater than or equal to the maximum charging power, the charging stops, at this time, the electric energy generated by the photovoltaic power generation module will be used for the load, or when there is a surplus of electric energy generated by the photovoltaic power generation module after supplying power to the load, the surplus part of the electric energy is connected to the grid for power selling.

[0062] In the non-charging mode, the photovoltaic energy storage device can charge the battery module, or use the electric energy stored in the battery module to supply power to the load. At this time, it is judged whether the battery power is greater than the power threshold, exemplarily, the power threshold is the minimum power threshold when the battery module is discharged, when the current battery power of the battery module is less than the minimum power threshold, it means that the power of the battery module is small, in order to avoid over-discharge or lockout of the battery, the battery module will not discharge externally at this time.

[0063] Therefore, when the photovoltaic energy storage device is in the non-charging mode and the current battery power of the battery module is greater than the power threshold, when the electric energy generated by the photovoltaic power generation cannot cover the entire power demand of the load, the battery module supplies power to the load until the current battery power of the battery module is less than or equal to the power threshold, the battery module stops discharging and charges the battery module when the condition allows.

[0064] The technical solutions of the present application can adaptively adjust the charging and discharging modes of the battery, avoid energy waste, and at the same time, reduce the power taken from the grid as much as possible to save electricity bills.

[0065] In some embodiments of the present application, the photovoltaic energy storage device further comprises a power storage conversion module and a photovoltaic inversion module; before determining the target working power of the battery module according to the grid power or the current battery power, the control method further comprises: determining the load power of the photovoltaic energy storage device according to the grid power, the inversion power of the power storage conversion module and the inversion power of the photovoltaic inversion module; determining the inversion power maximum of the power storage conversion module according to the load power and the maximum feed-in power; wherein the maximum feed-in power is used to indicate the maximum power value of the photovoltaic energy storage device feeding into the grid.

[0066] The control photovoltaic energy storage device according to the target working power to perform the target operation, comprising: controlling the photovoltaic energy storage device according to the target working power and the inversion power maximum to perform the target operation.

[0067] In this technical solution, the photovoltaic energy storage device comprises a power storage conversion module (PCS), which exemplarily comprises a DC / AC bidirectional converter control unit and the like, wherein the control unit receives the background control instruction through the communication unit, controls the charging or discharging of the battery module according to the sign and size of the power instruction, and realizes the adjustment of the active power and the reactive power of the micro-grid.

[0068] The photovoltaic inversion module is used to convert the direct current signal generated by photovoltaic power generation into an alternating current signal to supply power to the load or sell electricity to the grid.

[0069] Exemplarily, during the operation of the photovoltaic energy storage device, the power storage converter calculates the total load power according to the grid power, the inversion power of the power storage conversion module and the inversion power of the photovoltaic inversion module. Exemplarily, the load power can be calculated by the following formula (3):

[0070] Pload = Pgrid + Ppcs + Pacpv; (3)

[0071] Wherein, Pload is the load power, Pgrid is the grid power, Ppcs is the inversion power of the power storage conversion module, and Pacpv is the inversion power of the photovoltaic inversion module.

[0072] After obtaining the load power, the inversion power maximum of the power storage conversion module is calculated according to the load power and the maximum feed-in power, which exemplarily can be calculated by the following formula (4):

[0073] Ppcsmax = Pload + Pmaxsell - Pacpv; (4)

[0074] Wherein, Ppcsmax is the maximum inverter power of the energy storage converter module, Pload is the load power, Pacpv is the inverter power of the photovoltaic inverter module, Pmaxsell is the maximum feeding power, the maximum feeding power is the maximum power of the photovoltaic energy storage device feeding to the power grid, and Pmaxsell can be a fixed power value set in the program or a power value obtained by communicating with the upper device (such as a distribution box) of the power grid.

[0075] After obtaining the maximum inverter power of the energy storage converter module, the maximum inverter power of the energy storage converter module is used as the power instruction for controlling the operation of the energy storage converter module. By controlling the photovoltaic energy storage device to work through the power instruction, accurate adjustment of active power and reactive power can be realized, and the inverter power can be matched with the output power of the PV as much as possible within the range of the upper limit of the inverter power issued by the distribution box, thereby improving the energy efficiency of the photovoltaic energy storage device.

[0076] In some technical solutions of the present application, the control method further comprises updating the target working power and the maximum inverter power after the photovoltaic energy storage device performs the target operation according to the target working power and the maximum inverter power; and controlling the photovoltaic energy storage device to perform the target operation according to the updated target working power and the updated maximum inverter power when a preset condition is met; wherein the preset condition includes at least one of the following: the difference between the updated target working power and the previous target working power is greater than a power difference threshold, and the difference between the updated maximum inverter power and the previous maximum inverter power is greater than the power difference threshold.

[0077] In this technical solution, the photovoltaic energy storage device continuously updates the target working power and the maximum inverter power of the energy storage converter module during operation. When the difference between the updated target working power and the last issued target working power (the previous target working power) is greater than the power difference threshold, or when the difference between the updated maximum inverter power and the last issued maximum inverter power (the previous maximum inverter power) is greater than the power difference threshold, it indicates that the system load or photovoltaic power generation condition has changed. At this time, the updated data is issued to the energy storage converter module PCS through the Controller Area Network (CAN) bus, and the load and other parameters are recalculated according to the updated data, so as to control the energy storage converter module PCS to adjust the power instruction and the charging and discharging power of the battery module.

[0078] When the difference between the updated target operating power and the last issued target operating power is not greater than the power difference threshold, and the difference between the updated inverter power maximum value and the last issued inverter power maximum value is not greater than the power difference threshold, it indicates that the system state has not changed greatly, and the data change at this time may come from the acquisition error or temporary fluctuation. Therefore, the control control energy storage converter module PCS maintains the previous power regulation instruction and the charge and discharge power of the battery module unchanged, avoids frequent adjustment of the system control parameters, and ensures the system stability.

[0079] The second aspect of the present application provides a control device of a photovoltaic energy storage device. The photovoltaic energy storage device is electrically connected with a power grid and a load. The photovoltaic energy storage device comprises a battery module. The control device comprises:

[0080] An acquisition module is configured to acquire power grid power, current battery power of the battery module, and current time information. A determination module is configured to determine a current operating mode of the photovoltaic energy storage device according to the current time information, and determine a target operating power of the battery module according to the power grid power or the current battery power based on the current operating mode. A control module is configured to control the photovoltaic energy storage device to perform a target operation according to the target operating power based on the current operating mode. The target operation comprises charging the battery module and supplying power to the load by the battery module.

[0081] In the technical solution, the photovoltaic energy storage device is electrically connected with the power grid and the load. The photovoltaic energy storage device comprises the battery module. The battery module can comprise a plurality of battery cells. The photovoltaic energy storage device further comprises a photovoltaic power generation module. The photovoltaic energy storage device utilizes the phenomenon that a voltage is generated at the junction of a semiconductor and a metal when the photovoltaic energy storage device is exposed to light, to directly convert the radiant energy of the sun into electrical energy, thereby realizing photovoltaic power generation.

[0082] The electrical energy generated by the photovoltaic power generation can be directly provided to the load for use, or can be charged to the battery module, so that the electrical energy generated by the photovoltaic power generation is stored by the battery module. In a suitable condition, the load is supplied with power by the electrical energy stored in the battery module, thereby reducing the amount of power taken from the power grid, and reducing the electricity cost.

[0083] In some embodiments, the photovoltaic energy storage device can also realize grid connection, so as to deliver the surplus electrical energy of the photovoltaic power generation to the power grid, realize power selling to the power grid, and further generate a profit, which can also indirectly reduce the electricity cost of the household.

[0084] In order to better utilize the electric energy generated by photovoltaic power generation, how to reasonably allocate the charging and discharging power of the battery is an important key to affect the utilization rate of photovoltaic power generation. At the same time, keeping the battery in a reasonable and healthy power range is also conducive to improving the battery life. At the same time, when the power grid appears temporary power failure and other fluctuation faults, enough power is reserved to temporarily supply power to the load, reducing the impact of power failure on power consumption.

[0085] Therefore, the technical scheme of the present application proposes a control method of a photovoltaic energy storage device. The method divides the working mode of the photovoltaic energy storage device based on time period, such as charging time period and non-charging time period. The charging time period refers to the time period for preferentially charging the battery. For example, the charging time period can be selected as the time period with small load and less power consumption scenario, such as daytime on weekdays. At this time, the household power consumption is small, but the illumination is generally sufficient. Therefore, these time periods can be used to preferentially charge the battery module and store electric energy. The charging time period can also be selected as the time period with price in trough. For example, the photovoltaic energy storage device receives the price trough time period issued by the power grid through the communication protocol, and preferentially charges the battery module in the price trough time period. The non-charging time period can dynamically switch the charging and discharging mode of the battery according to the load, power generation and other specific working conditions, so as to ensure the utilization rate of photovoltaic energy.

[0086] For example, the photovoltaic energy storage device determines the current working mode according to the acquired current time information, and selects the target working power of the battery module according to the power grid power or the real-time point battery power at the current time point according to different working modes. The target working power is the power of the battery module when charging or discharging.

[0087] For example, the positive and negative values of the target working power can be used to determine whether the battery module is charging or supplying power to the load. For example, assuming that the current direction in the photovoltaic energy storage device is the direction pointing to the AC bus, the target working power is positive, and the battery module is in the discharging state. When the current direction in the photovoltaic energy storage device is opposite to the direction of the AC bus, the target working power is negative, and the battery module is in the charging state.

[0088] After determining the current working mode of the photovoltaic energy storage device and the target working power of the battery module in the current working mode, the photovoltaic energy storage device automatically performs corresponding target operations according to the current working mode and the target working power, where the target working power is the power on the grid side. For example, when the target working mode is the charging mode, the photovoltaic energy storage device charges the battery module with the target working power as the charging power. For example, when the target working mode is the non-charging mode and the target working power is positive, the battery module is controlled to supply power to the load with the target working power as the discharging power.

[0089] The technical scheme of the present application divides the working mode of the photovoltaic energy storage device based on the time period, and dynamically adjusts the charging power or discharging power of the battery module according to different working modes, so that the target working power of the battery module can always match the actual working condition of the photovoltaic energy storage device, thereby improving the energy utilization rate of photovoltaic power generation.

[0090] The third aspect of the present application provides a control device of a photovoltaic energy storage device, which comprises a memory for storing programs or instructions, and a processor for executing the programs or instructions to realize the steps of the control method of the photovoltaic energy storage device provided in any of the above technical solutions, thus also including all the beneficial effects of the control method of the photovoltaic energy storage device provided in any of the above technical solutions, which will not be repeated here to avoid repetition.

[0091] The fourth aspect of the present application provides a readable storage medium having programs or instructions stored thereon, which are executed by a processor to realize the steps of the control method of the photovoltaic energy storage device provided in any of the above technical solutions, thus also including all the beneficial effects of the control method of the photovoltaic energy storage device provided in any of the above technical solutions, which will not be repeated here to avoid repetition.

[0092] The fifth aspect of the present application provides a photovoltaic energy storage device comprising the control device of the photovoltaic energy storage device provided in any of the above technical solutions and / or the readable storage medium provided in any of the above technical solutions, thus also including all the beneficial effects of the control device of the photovoltaic energy storage device and the readable storage medium provided in any of the above technical solutions, which will not be repeated here to avoid repetition. BRIEF DESCRIPTION OF DRAWINGS

[0093] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:

[0094] Figure 1 A flowchart of the control method of the photovoltaic energy storage device of some embodiments of the present application is shown;

[0095] Figure 2A charge-discharge logic diagram of the photovoltaic energy storage device is shown to illustrate some embodiments of the present application.

[0096] Figure 3 A flow chart of a control method of the photovoltaic energy storage device is shown to illustrate some embodiments of the present application.

[0097] Figure 4 A structural block diagram of a control device of the photovoltaic energy storage device is shown to illustrate some embodiments of the present application.

[0098] Figure 5 A structural block diagram of a control device of the photovoltaic energy storage device is shown to illustrate some embodiments of the present application. DETAILED DESCRIPTION

[0099] In order to enable a clearer understanding of the above-mentioned purposes, features and advantages of the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0100] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application, however, the present application can also be implemented in other ways different from those described herein, therefore, the scope of protection of the present application is not limited by the specific embodiments disclosed below.

[0101] The following refers to Figures 1 to 5 The control method and device, the storage medium and the photovoltaic energy storage device according to some embodiments of the present application are described.

[0102] In some embodiments of the present application, a control method of a photovoltaic energy storage device is provided, the photovoltaic energy storage device is electrically connected with a power grid and a load, the photovoltaic energy storage device includes a battery module, Figure 1 A flow chart of a control method of the photovoltaic energy storage device is shown to illustrate some embodiments of the present application, as Figure 1 As shown, the control method includes:

[0103] Step 102, acquiring power grid power, current battery power of the battery module and current time information;

[0104] Step 104, determining a current working mode of the photovoltaic energy storage device according to the current time information;

[0105] Step 106, determining a target working power of the battery module according to the power grid power or the current battery power based on the current working mode;

[0106] Step 108, controlling the photovoltaic energy storage device to perform a target operation according to the target working power based on the current working mode; wherein the target operation includes charging the battery module and supplying power to the load through the battery module.

[0107] In this embodiment, the photovoltaic energy storage device is electrically connected to the power grid and the load, and the photovoltaic energy storage device includes a battery module, which can include a plurality of battery cells. The photovoltaic energy storage device also includes a photovoltaic (PV) power generation module, which directly converts solar radiation energy into electrical energy by using the phenomenon that a semiconductor and a metal combined part generates a voltage when exposed to light, thereby realizing photovoltaic power generation.

[0108] The electrical energy generated by photovoltaic power generation can be directly provided to the load for use, or can be charged to the battery module, so that the electrical energy generated by photovoltaic power generation is stored through the battery module. In the case of suitable conditions, the load is powered by the electrical energy stored in the battery module, thereby reducing the amount of electricity taken from the power grid and reducing the cost of electricity.

[0109] In some embodiments, the photovoltaic energy storage device can also realize grid connection, so as to deliver the excess electrical energy generated by photovoltaic power generation to the power grid, realize power selling to the power grid, and thereby generate income, which can also indirectly reduce the cost of electricity for the household.

[0110] In order to better utilize the electrical energy generated by photovoltaic power generation, how to reasonably allocate the charging and discharging power of the battery is an important key to the utilization rate of photovoltaic power generation. At the same time, keeping the battery in a reasonable and healthy power range is also conducive to improving the battery life. At the same time, when the power grid appears temporary power failure and other fluctuation faults, sufficient power is reserved to temporarily supply power to the load, reducing the impact of power failure on electricity.

[0111] Therefore, an embodiment of the present application proposes a control method of a photovoltaic energy storage device, which divides the working mode of the photovoltaic energy storage device based on time period, such as charging time period and non-charging time period. The charging time period refers to the time period for preferentially charging the battery. For example, the charging time period can be selected as a time period with small load and less electricity scenario, such as daytime on weekdays. At this time, the household electricity consumption is small, but the illumination is generally sufficient, so the battery module can be preferentially charged to store electrical energy. The charging time period can also be selected as a time period with a wave trough of electricity price. For example, the photovoltaic energy storage device receives the wave trough time period of electricity price issued by the power grid through a communication protocol, and preferentially charges the battery module in the wave trough time period of electricity price. The non-charging time period can dynamically switch the charging and discharging modes of the battery according to the load, power generation capacity and other specific working conditions, so as to ensure the utilization rate of photovoltaic energy.

[0112] Exemplarily, the photovoltaic energy storage device determines a current working mode of itself according to the obtained current time information, and selects to determine the target working power of the battery module according to the grid power or according to the real-time point battery power of the battery module at the current time point according to different working modes, where the target working power is the power when the battery module charges or discharges.

[0113] Exemplarily, whether the battery module charges or supplies power to the load can be determined by the positive or negative value of the target working power. For example, assuming that the current direction in the photovoltaic energy storage device is the direction pointing to the AC busbar, the target working power is positive, and at this time, the battery module is in a discharging state. When the current direction in the photovoltaic energy storage device is the direction away from the AC busbar, the target working power is negative, and at this time, the battery module is in a charging state.

[0114] After determining the current working mode of the photovoltaic energy storage device and the target working power of the battery module in the current working mode, the photovoltaic energy storage device automatically performs corresponding target operations according to the current working mode and the target working power, where the target working power is the power on the grid side. Exemplarily, when the target working mode is a charging mode, the photovoltaic energy storage device charges the battery module with the target working power as the charging power. Exemplarily, when the target working mode is a non-charging mode and the target working power is positive, the battery module is controlled to supply power to the load with the target working power as the discharging power.

[0115] The embodiment of the present application divides the working mode of the photovoltaic energy storage device based on the time period, and dynamically adjusts the charging power or discharging power of the battery module according to different working modes, so that the target working power of the battery module can always match the actual working condition of the photovoltaic energy storage device, and the energy utilization rate of photovoltaic power generation is improved.

[0116] In some embodiments of the present application, optionally, determining the current working mode of the photovoltaic energy storage device according to the current time information includes: in the case that the current time information is in the charging time period, determining that the current working mode is a charging mode; or in the case that the current time information is out of the charging time period, determining that the current working mode is a non-charging mode.

[0117] In this embodiment, the time period in a natural day is divided in units of hours or minutes, and the charging time period and the non-charging time period are divided. The photovoltaic energy storage device can obtain the current time information through networking or according to its own timer, and determine whether the current time information is in the charging time period or in the non-charging time period.

[0118] If it is judged that the current time information is in the charging time period, it is determined that the current working mode of the photovoltaic energy storage device is the charging mode, and if it is judged that the current time information is not in the charging time period, it is determined that the current working mode of the photovoltaic energy storage device is the non-charging mode.

[0119] For example, assuming that the time period of 11:00-15:00 in a day is set as the charging time period, and the current time information is 12:45, it is determined that the current working mode is the charging mode.

[0120] For example, assuming that the time period of 13:00-16:00 in a day is set as the charging time period, and the current time information is 19:00, it is determined that the current working mode is the non-charging mode.

[0121] It can be understood that the charging time period can be dynamically adjusted for changes such as weekdays and non-weekdays, holidays and non-holidays, different seasons, etc.

[0122] It can be understood that the user can freely set the charging time period through the control panel or other electronic device programs connected to the photovoltaic energy storage device.

[0123] The embodiments of the present application can improve the energy utilization rate of photovoltaic power generation by setting the charging time period to distinguish the working mode of the photovoltaic energy storage device.

[0124] In some embodiments of the present application, optionally, based on the current working mode, the target working power of the battery module is determined according to the grid power or the current battery power, comprising: in the case that the current working mode is the charging mode, obtaining the charging configuration information of the photovoltaic energy storage device; in the case that the charging configuration information is to charge the battery module through the grid, and the current battery power is less than the maximum charging power of the battery module, determining a first working power according to the maximum charging power, the current battery power, the charging time period and the current time information; and determining the target working power according to the first working power.

[0125] In this embodiment, if it is determined that the current time information is in the charging time period, that is, the current working mode of the photovoltaic energy storage device is the charging mode, the charging configuration information is obtained, and the charging configuration information sets that the photovoltaic energy storage device can use the power of the grid to charge the battery module.

[0126] When the charging configuration information allows charging the battery module through the grid, the photovoltaic energy storage device can simultaneously use the surplus power of the photovoltaic power generation module and the power supplied by the grid to charge the battery module, thereby improving the charging speed, ensuring that the power of the battery module can always be maintained at a relatively high power level, so as to be used when the grid fails temporarily, and reducing the impact of power failure.

[0127] When the charging configuration information does not allow the battery module to be charged through the power grid, the photovoltaic energy storage device intelligently charges the battery module with surplus power generated by the photovoltaic power generation module, thereby minimizing the consumption of power grid power and the cost of electricity.

[0128] If it is determined that the current working mode of the photovoltaic energy storage device is the charging mode and the charging configuration information allows charging through the power grid, it is determined whether the current battery power (State Of Charge, SOC) reaches the maximum charging power, which is the power threshold when charging the battery module. If the current battery power does not reach the maximum charging power, the first working power is determined according to the maximum charging power, the current battery power, the charging time period and the current time information.

[0129] Exemplarily, the first working power is calculated by the following formula (1):

[0130] Psmoothcharge = (SOCmax-SOC)÷(t2-t1); (1)

[0131] Wherein, Psmoothcharge is the first working power, SOCmax is the maximum charging power, SOC is the current battery power, t2 is the end time point of the charging time period, and t1 is the time point corresponding to the current time information.

[0132] It can be understood that the first working power here is the working power that fully utilizes the charging time period to smoothly charge the battery module to the maximum charging power. The target working power when charging the battery module is determined according to the first working power, which can smoothly charge the battery module. When the photovoltaic power generation surplus is insufficient, the battery module can be smoothly charged by taking power from the power grid.

[0133] The embodiment of the application can smoothly charge the battery module, so that the battery module can always be fully charged at the end of the charging time period, ensuring the battery charging efficiency.

[0134] In some embodiments of the application, optionally, based on the current working mode, the target working power of the battery module is determined according to the power grid power or the current battery power, including: when the current working mode is the charging mode, obtaining the charging configuration information of the photovoltaic energy storage device; when the charging configuration information is to charge the battery module through the power grid and the current battery power is greater than or equal to the maximum charging power of the battery module, or when the charging configuration information is not to charge the battery module through the power grid, the first working power is determined according to the power grid power and the current working power of the battery module; and the target working power is determined according to the first working power.

[0135] In this embodiment, if the current working mode of the photovoltaic energy storage device is the charging mode, the charging configuration information allows charging through the power grid, but the current battery capacity has reached or exceeded the maximum charging capacity, the battery module no longer charges, and the first working power is determined according to the current working power of the battery module and the power grid power.

[0136] If it is determined that the current working mode of the photovoltaic energy storage device is the charging mode, and the charging configuration information does not allow charging through the power grid, then the photovoltaic energy storage device can only charge the battery module through the surplus power of the photovoltaic power generation module at this time. It can be understood that the above-mentioned surplus power refers to the part of the power generated by the photovoltaic power generation module after deducting the part of the power directly used for power supply to the load, and the first working power is determined according to the current working power of the battery module and the power grid power at this time.

[0137] Exemplarily, the first working power is calculated by the following formula (2):

[0138] PObjabt1 = Pbat + Pgrid; (2)

[0139] Wherein, PObjabt1 is the first working power, Pbat is the current working power, and Pgrid is the power grid power.

[0140] Exemplarily, in the charging mode, the battery will not discharge externally, and after the current battery capacity of the battery module reaches the maximum charging capacity, the battery module will not charge, and the charging power of the battery module, i.e. the current working power, is 0, and the power grid power is the data obtained by the power grid metering module. When the power grid is connected to the power grid and the power is fed to the power grid, the power grid power is negative, and when the power is taken from the power grid, the power grid power is positive.

[0141] For the case where the current battery capacity reaches the maximum charging capacity, if the power grid power is negative, the first working power is negative, and the first working power being negative indicates that the battery module charges according to the working power. However, since the battery module is full at this time, the actual target charging power is 0. If the power grid power is positive, the first working power is also positive, and the first working power being positive indicates that the battery module discharges according to the working power. However, since it is in the charging mode at this time, the battery module will not discharge externally, and therefore the actual target charging power is also 0.

[0142] For the case that the battery module is not allowed to be charged by the grid power, if the grid power is negative, the first working power is negative, and the first working power being negative indicates that the battery module is charged according to the working power. If the grid power is positive, the first working power is positive, and the first working power being positive indicates that the battery module is discharged according to the working power, and since the battery module is in the charging mode at this time, the battery module will not discharge externally, and thus the target charging power is actually 0.

[0143] The embodiment of the present application can reasonably allocate the battery charging power according to the current battery power and whether the battery is allowed to be charged by the grid, so as to realize full utilization of the photovoltaic power and improve the energy utilization rate of photovoltaic power generation.

[0144] In some embodiments of the present application, the target working power of the battery module is determined according to the grid power or the current battery power based on the current working mode, including: in the case that the current working mode is the non-charging mode, determining the first working power according to the grid power and the current working power of the battery module; and determining the target working power according to the first working power.

[0145] In this embodiment, if the current working mode of the photovoltaic energy storage device is the non-charging mode, the battery module can discharge externally to supply power to the load by the energy stored in the battery module when the condition is met, at this time, the first working power is determined according to the current working power of the battery module and the grid power. Exemplarily, the first working power is calculated by the above formula (2).

[0146] In the non-charging mode, the battery module can discharge externally, assuming that the battery module is in the discharging state, the current working power of the battery module is positive, and when the battery module is in the charging state, the current working power of the battery module is negative. Similarly, the grid power is negative when the photovoltaic energy storage device is connected to the grid to output power to the grid, and the grid power is positive when power is taken from the grid.

[0147] After calculation by formula (2), if the first working power is positive, the battery module is controlled to discharge according to the finally determined target working power, and if the first working power is negative, the battery module is controlled to charge according to the finally determined target working power.

[0148] The embodiment of the present application can dynamically adjust the target working power of the battery module to charge or discharge in the non-charging mode according to the grid power and the current working power of the battery module, which can effectively improve the energy utilization rate of photovoltaic power generation.

[0149] In some embodiments of the present application, the target working power is determined according to the first working power, including: in a case where the first working power is less than or equal to the maximum working power of the battery module, the first working power is determined as the target working power; or in a case where the first working power is greater than the maximum working power of the battery module, the first threshold power is determined as the target working power.

[0150] In this embodiment, the maximum working power of the battery module is a power threshold of the battery module when charging or discharging, and when the current working power of the battery module is greater than the maximum working power, problems such as heating of the battery may be caused, affecting the safety of power consumption.

[0151] Therefore, after the first working power is calculated, the greater one between the first working power and the maximum working power is taken as the target power of the battery.

[0152] For example, when the first working power is a charging power (a negative value) and the absolute value of the first working power is greater than the charging power threshold of the battery module (the absolute value of the maximum working power), the maximum working power of the battery module is set as the target working power, that is, the battery module is charged by the maximum charging power.

[0153] For example, when the first working power is a discharging power (a positive value) and the absolute value of the first working power is less than the discharging power threshold of the battery module (the absolute value of the maximum working power), the first working power is set as the target working power, that is, the battery module is controlled to supply power to the load by the first working power.

[0154] By selecting the greater one between the first working power and the maximum working power as the target working power, the embodiments of the present application can ensure the working safety of the battery module while ensuring the charging and discharging efficiency, and improve the reliability of the photovoltaic energy storage device.

[0155] In some embodiments of the present application, optionally, the current working mode includes a charging mode and a non-charging mode; based on the current working mode, the photovoltaic energy storage device is controlled to perform a target operation according to the target working power, including: in a case where the current working mode is the charging mode and the current battery power is less than the maximum charging power, the photovoltaic energy storage device is controlled to charge the battery module according to the target working power; or in a case where the current working mode is the non-charging mode and the current battery power is greater than the power threshold, the photovoltaic energy storage device is controlled to supply power to the load according to the target working power.

[0156] In the charging mode, the photovoltaic energy storage device preferentially ensures the charging process of the battery module. If the current battery capacity does not reach the maximum charging capacity, that is, the battery module is not full, the battery module is charged by the determined target working power until the current battery capacity of the battery module is greater than or equal to the maximum charging capacity, and the charging stops. At this time, the power generated by the photovoltaic power generation module is used for load use, or when there is still surplus after the power generated by the photovoltaic power generation module is used for load power supply, the surplus part of the power is connected to the power grid for power selling.

[0157] In the non-charging mode, the photovoltaic energy storage device can charge the battery module or use the power stored in the battery module to supply power to the load. At this time, it is judged whether the battery capacity is greater than the capacity threshold. Exemplarily, the capacity threshold is the minimum capacity threshold when the battery module is discharged. When the current battery capacity of the battery module is less than the minimum capacity threshold, it indicates that the battery capacity is small. In order to avoid over-discharge or lockout of the battery, the battery module will not discharge externally at this time.

[0158] Therefore, when the photovoltaic energy storage device is in the non-charging mode and the current battery capacity of the battery module is greater than the capacity threshold, the battery module supplies power to the load when the power generated by the photovoltaic power generation cannot cover the entire power demand of the load, until the current battery capacity of the battery module is less than or equal to the capacity threshold, the battery module stops discharging, and the battery module is charged when the condition allows.

[0159] The embodiment of the application can adaptively adjust the charging and discharging modes of the battery, avoid energy waste, and reduce the power taken from the power grid as much as possible to save electricity bills.

[0160] In some embodiments of the application, the photovoltaic energy storage device further comprises an energy storage conversion module and a photovoltaic inversion module. Before determining the target working power of the battery module according to the grid power or the current battery capacity, the control method further comprises: determining the load power of the photovoltaic energy storage device according to the grid power, the inversion power of the energy storage conversion module and the inversion power of the photovoltaic inversion module; determining the inversion power maximum of the energy storage conversion module according to the load power and the maximum feed power. The maximum feed power is used to indicate the maximum power value of the photovoltaic energy storage device feeding to the power grid.

[0161] The control photovoltaic energy storage device according to the target working power to perform the target operation, comprising: controlling the photovoltaic energy storage device according to the target working power and the inversion power maximum to perform the target operation.

[0162] In this embodiment, the photovoltaic energy storage device includes a power conversion system (PCS), which exemplarily includes a DC / AC bidirectional converter control unit and the like. The control unit receives a background control instruction through a communication unit, controls the charging or discharging of the battery module according to the sign and size of the power instruction, and realizes the adjustment of the active power and the reactive power of the microgrid.

[0163] The photovoltaic inverter module is used to convert the direct current signal generated by photovoltaic power generation into an alternating current signal to supply power to the load or to sell electricity to the grid.

[0164] Exemplarily, during the operation of the photovoltaic energy storage device, the energy storage converter calculates the total load power according to the grid power, the inverter power of the energy storage conversion module and the inverter power of the photovoltaic inverter module. Exemplarily, the load power can be calculated by the following formula (3):

[0165] Pload = Pgrid + Ppcs + Pacpv; (3)

[0166] Wherein, Pload is the load power, Pgrid is the grid power, Ppcs is the inverter power of the energy storage conversion module, and Pacpv is the inverter power of the photovoltaic inverter module.

[0167] After obtaining the load power, the maximum inverter power of the energy storage conversion module is calculated according to the load power and the maximum feed-in power. Exemplarily, the maximum inverter power of the energy storage conversion module can be calculated by the following formula (4):

[0168] Ppcsmax = Pload + Pmaxsell - Pacpv; (4)

[0169] Wherein, Ppcsmax is the maximum inverter power of the energy storage conversion module, Pload is the load power, Pacpv is the inverter power of the photovoltaic inverter module, and Pmaxsell is the maximum feed-in power, i.e. the maximum power of the photovoltaic energy storage device feeding into the grid. Pmaxsell can be a fixed power value set in the program or a power value obtained by communicating with the upper device of the grid (such as a distribution box).

[0170] After the maximum inverter power of the energy storage and conversion module is obtained, the maximum inverter power of the energy storage and conversion module is used as a power instruction for controlling the energy storage and conversion module to work, and the photovoltaic energy storage device is controlled to work through the power instruction, so that accurate adjustment of active power and reactive power can be realized, and the inverter power is matched with the output power of the PV as much as possible within the upper limit of the inverter power issued by the distribution box, and the energy efficiency of the photovoltaic energy storage device is improved.

[0171] In some embodiments of the present application, optionally, after the photovoltaic energy storage device is controlled to perform the target operation according to the target working power and the maximum inverter power, the control method further comprises: updating the target working power and the maximum inverter power; and in the case that a preset condition is met, controlling the photovoltaic energy storage device to perform the target operation according to the updated target working power and the updated maximum inverter power; wherein the preset condition comprises at least one of the following: a difference between the updated target working power and the target working power before the update is greater than a power difference threshold, and a difference between the updated maximum inverter power and the maximum inverter power before the update is greater than the power difference threshold.

[0172] In this embodiment, the photovoltaic energy storage device continuously updates the target working power and the maximum inverter power of the energy storage and conversion module during the working process. When the difference between the updated target working power and the target working power issued last time (the target working power before the update) is greater than the power difference threshold, or when the difference between the updated maximum inverter power and the maximum inverter power issued last time (the maximum inverter power before the update) is greater than the power difference threshold, it indicates that the system load or the photovoltaic power generation condition has changed. At this time, the updated data is issued to the energy storage and conversion module PCS through the Controller Area Network (CAN) bus, and the load and the like are recalculated according to the updated data, so as to control the energy storage and conversion module PCS to adjust the power instruction and the charging and discharging power of the battery module.

[0173] When the difference between the updated target working power and the target working power issued last time is not greater than the power difference threshold, and the difference between the updated maximum inverter power and the maximum inverter power issued last time is not greater than the power difference threshold, it indicates that the system state has not changed greatly. At this time, the data change may come from the acquisition error or temporary fluctuation, so the energy storage and conversion module PCS is controlled to maintain the previous power adjustment instruction and the charging and discharging power of the battery module unchanged, so as to avoid frequent adjustment of the system control parameters and ensure the stability of the system.

[0174] In some embodiments of the present application, Figure 2 A charging and discharging logic diagram of the photovoltaic energy storage device of some embodiments of the present application is shown as follows: Figure 2As shown, when the battery reaches the lowest SOC of discharging, the battery no longer outputs until the battery SOC recovers to the sum of the lowest SOC and the hysteresis value, exemplarily, the hysteresis value is 5%. During the charging time period, the battery does not output.

[0175] Figure 3 A flow chart of a control method of a photovoltaic energy storage device of some embodiments of the present application is shown as follows. Figure 3 As shown, the control method comprises:

[0176] Step 302, calculating the load power;

[0177] Step 304, calculating the maximum inverter power;

[0178] Step 306, judging whether it is a charging time period; if yes, going to step 308, otherwise going to step 314;

[0179] Step 308, judging whether it is allowed to take power from the grid to charge the battery; if yes, going to step 310, otherwise going to step 314;

[0180] Step 310, judging whether the current SOC is less than the maximum charging SOC; if yes, going to step 312, otherwise going to step 314;

[0181] Step 312, the first working power is the smooth charging power;

[0182] Step 314, the first working power is the sum of the current working power and the grid power;

[0183] Step 316, the first target working power takes the larger one of the first working power and the maximum charging power;

[0184] Step 318, judging whether it is allowed to discharge; if yes, going to step 320, otherwise going to step 322;

[0185] Step 320, the second target working power takes the smaller one of the first target working power and the maximum discharging power;

[0186] Step 322, the second target working power takes the smaller one of the first target working power and 0;

[0187] Step 324, issuing the maximum inverter power and the second target working power to the PCS.

[0188] Wherein, step one: according to the law of conservation of energy, calculating the total load power Pload=grid power (Pgrid, collected) + PCS inverter power (Ppcs, reported by PCS) + AC inverter power (Pacpv, collected).

[0189] Step two: calculate the PCS inverter power upper limit (Ppcsmax) = load (Pload) + selling quota (Pmaxsell, APP configuration) - photovoltaic (AC) inverter power (Pacpv, collected).

[0190] Step three: determine whether it is currently a charging time period, if not, go to step seven.

[0191] Step four: confirm whether the user allows to take power from the grid to charge the battery, if not allowed, only PV power surplus to charge the battery, go to step seven.

[0192] Step five: determine whether the current SOC is less than the maximum SOC of the battery, if not, only PV power surplus to charge the battery, go to step seven.

[0193] Step six: according to the battery capacity of the battery charging maximum SOC, the current capacity of the battery, the duration of the charging time period, calculate the smooth charging power of the battery (six minutes timer), go to step eight.

[0194] Step seven: according to the current power situation of the grid, calculate the battery target power = battery current power + grid power.

[0195] Step eight: make minimum value judgment on the battery target power, the maximum value of the battery target power and the battery charging power (charging power is negative) as the battery target power.

[0196] Step nine: determine whether the battery is allowed to discharge, the judgment logic is as follows:

[0197] 1) for charging time period, the discharge permission flag is assigned value 0, not allowed to discharge;

[0198] 2) not for charging time period, determine whether to allow discharge according to the following conditions:

[0199] The current battery SOC is less than or equal to the minimum discharge SOC, the discharge permission flag is assigned value 0, not allowed to discharge;

[0200] The current SOC is greater than or equal to the minimum discharge SOC + difference, the discharge permission flag is assigned value 1, allowed to discharge;

[0201] 3) the battery reaches the minimum SOC of over-discharge, and the current SOC is less than the minimum SOC of discharge + hysteresis difference, then not allowed to discharge.

[0202] Step ten: if the battery is not allowed to discharge, the minimum value of the battery target power and 0 is taken as the final target power of the battery; if the battery is allowed to discharge, the minimum value of the battery target power and the battery discharge upper limit is taken as the final target power of the battery.

[0203] Step eleven: determine whether the PCS inverter power upper limit or battery target power and the last time issued is changed more than 300W, if so, the PCS inverter power upper limit and battery target power are issued to the PCS through the high-speed CAN, hibernate for 100ms, and go to step one.

[0204] In the grid-connected case, the PCS inverter power control logic is:

[0205] (1) The distribution box issues the inverter power upper limit to the PCS, and the PCS tries to pursue PV within the upper limit range, and ensures that the inverter output cannot be greater than the upper limit.

[0206] (2) The distribution box issues the battery target power difference to the PCS, and the PCS responds in real time and adjusts the battery power to the target difference. The distribution box indirectly controls the PCS inverter power through the battery target power difference.

[0207] The battery power control logic is:

[0208] Feeding to the grid or the feeding power being greater than the selling power quota indicates that the PCS inverter output is too much, and the battery reduces the output power or increases the battery charging power.

[0209] The grid has input, which indicates that the PCS inverter output is insufficient, and the battery increases the output power.

[0210] In some embodiments of the present application, a control device of a photovoltaic energy storage device is provided, the photovoltaic energy storage device is electrically connected with a grid and a load, the photovoltaic energy storage device includes a battery module, Figure 4 The structure block diagram of the control device of the photovoltaic energy storage device of some embodiments of the present application is shown as follows: Figure 4 As shown in the figure, the control device 400 includes:

[0211] The acquisition module 402 is configured to acquire grid power, current battery capacity of the battery module, and current time information; the determination module 404 is configured to determine a current working mode of the photovoltaic energy storage device according to the current time information, and determine a target working power of the battery module according to the grid power or the current battery capacity based on the current working mode; and the control module 406 is configured to control the photovoltaic energy storage device to perform a target operation according to the target working power based on the current working mode; wherein the target operation includes charging the battery module and supplying power to the load through the battery module.

[0212] In this embodiment, the photovoltaic energy storage device is electrically connected with a grid and a load, the photovoltaic energy storage device includes a battery module, the battery module can include a plurality of battery cells, and the photovoltaic energy storage device also includes a photovoltaic power generation module, which uses the phenomenon that a semiconductor and a metal combined part generates a voltage to directly convert solar radiant energy into electrical energy, thereby realizing photovoltaic power generation.

[0213] The electric energy generated by the photovoltaic power generation can be directly provided to the load, or can be charged to the battery module, so that the electric energy generated by the photovoltaic power generation is stored through the battery module, and in a suitable condition, the load is powered by the electric energy stored in the battery module, thereby reducing the amount of electricity taken from the power grid and reducing the electricity cost.

[0214] In some embodiments, the photovoltaic energy storage device can also realize grid connection, so as to deliver the surplus electric energy of the photovoltaic power generation to the power grid, realize power selling to the power grid, and further generate income, which can also indirectly reduce the electricity cost of the household.

[0215] In order to better utilize the electric energy generated by the photovoltaic power generation, how to reasonably allocate the charging and discharging power of the battery is an important key to the utilization rate of the photovoltaic power generation, and at the same time, keeping the battery in a reasonable and healthy power range is also conducive to improving the battery life, and at the same time, when the power grid appears temporary power failure and other fluctuation faults, sufficient power is reserved to temporarily power the load, reducing the impact of power failure on electricity.

[0216] Therefore, an embodiment of the present application proposes a control method of a photovoltaic energy storage device, which divides the working mode of the photovoltaic energy storage device based on time period, such as charging time period and non-charging time period. The charging time period refers to the time period for preferentially charging the battery. For example, the charging time period can be selected as the time period with small load and less electricity scene, such as daytime on weekdays. At this time, the household electricity consumption is small, but the illumination is generally sufficient, so the battery module can be preferentially charged to store electric energy. The charging time period can also be selected as the time period with price in trough. For example, the photovoltaic energy storage device receives the price trough time period issued by the power grid through the communication protocol, and preferentially charges the battery module in the price trough time period. The non-charging time period can dynamically switch the charging and discharging mode of the battery according to the load, power generation and other specific working conditions, so as to ensure the utilization rate of photovoltaic energy.

[0217] For example, the photovoltaic energy storage device determines the current working mode according to the obtained current time information, and selects the target working power of the battery module according to the grid power or the real-time point battery power of the battery module at the current time point according to different working modes. The target working power is the power of the battery module when charging or discharging.

[0218] Exemplarily, whether the battery module is charging or supplying power to the load can be determined by the positive or negative value of the target operating power. For example, assuming that the current direction in the photovoltaic energy storage device is the direction pointing to the AC busbar, the target operating power is positive, and the battery module is in the discharging state. When the current direction in the photovoltaic energy storage device is the direction away from the AC busbar, the target operating power is negative, and the battery module is in the charging state.

[0219] After determining the current operating mode of the photovoltaic energy storage device and the target operating power of the battery module in the current operating mode, the photovoltaic energy storage device automatically performs the corresponding target operation according to the current operating mode and the target operating power, where the target operating power is the power on the grid side. Exemplarily, when the target operating mode is the charging mode, the photovoltaic energy storage device charges the battery module with the target operating power as the charging power. Exemplarily, when the target operating mode is the non-charging mode and the target operating power is positive, the battery module is controlled to supply power to the load with the target operating power as the discharging power.

[0220] The embodiment of the present application divides the operating mode of the photovoltaic energy storage device based on the time period, and dynamically adjusts the charging power or discharging power of the battery module according to different operating modes, so that the target operating power of the battery module can always match the actual operating condition of the photovoltaic energy storage device, and the energy utilization rate of photovoltaic power generation is improved.

[0221] In some embodiments of the present application, the determining module is further configured to determine that the current operating mode is the charging mode when the current time information is in the charging time period, or determine that the current operating mode is the non-charging mode when the current time information is out of the charging time period.

[0222] In this embodiment, the time period in a natural day is divided into hours or minutes, and the charging time period and the non-charging time period are obtained. The photovoltaic energy storage device can obtain the current time information through networking or according to its own timer, and determine whether the current time information is in the charging time period or the non-charging time period.

[0223] If it is determined that the current time information is in the charging time period, it is determined that the current operating mode of the photovoltaic energy storage device is the charging mode. If it is determined that the current time information is not in the charging time period, it is determined that the current operating mode of the photovoltaic energy storage device is the non-charging mode.

[0224] Exemplarily, assuming that the time period from 11:00 to 15:00 in a day is set as the charging time period, and the current time information is 12:45, it is determined that the current operating mode is the charging mode.

[0225] Exemplarily, assuming that the time period from 13:00 to 16:00 in a day is set as the charging time period, and the current time information is 19:00, it is determined that the current working mode is the non-charging mode.

[0226] It can be understood that the charging time period can be dynamically adjusted for changes in weekdays and non-weekdays, holidays and non-holidays, different seasons, etc.

[0227] It can be understood that the user can freely set the charging time period through the control panel or other electronic device programs connected to the photovoltaic energy storage device.

[0228] The embodiments of the present application can improve the energy utilization rate of photovoltaic power generation by setting the charging time period to distinguish the working mode of the photovoltaic energy storage device.

[0229] In some embodiments of the present application, the acquisition module is also configured to acquire charging configuration information of the photovoltaic energy storage device when the current working mode is the charging mode; the determination module is also configured to determine a first working power according to the maximum charging power, the current battery power, the charging time period and the current time information when the charging configuration information is that the battery module is charged through the power grid, and the current battery power is less than the maximum charging power of the battery module; and determine the target working power according to the first working power.

[0230] In this embodiment, if it is determined that the current time information is within the charging time period, that is, the current working mode of the photovoltaic energy storage device is the charging mode, the charging configuration information is acquired, and the charging configuration information sets that the photovoltaic energy storage device can charge the battery module using the power energy of the power grid.

[0231] When the charging configuration information allows the battery module to be charged through the power grid, the photovoltaic energy storage device can simultaneously use the surplus power energy of the photovoltaic power generation module and the power energy supplied by the power grid to charge the battery module, thereby improving the charging speed and ensuring that the power of the battery module can always be maintained at a relatively high power level for use in case of temporary power failure of the power grid and the like, thereby reducing the impact of power failure.

[0232] When the charging configuration information does not allow the battery module to be charged through the power grid, the photovoltaic energy storage device intelligently uses the surplus power energy of the photovoltaic power generation module to charge the battery module, thereby minimizing the consumption of power grid power and minimizing electricity expenses.

[0233] If it is determined that the current working mode of the photovoltaic energy storage device is the charging mode, and the charging configuration information allows charging through the power grid, it is determined whether the current battery state of charge (SOC) reaches the maximum charging capacity, which is the capacity threshold when charging the battery module, if the current battery state of charge does not reach the maximum charging capacity, the first working power is determined according to the maximum charging capacity, the current battery state of charge, the charging time period and the current time information.

[0234] Exemplarily, the first working power is calculated by the following formula (1):

[0235] Psmoothcharge=(SOCmax-SOC)÷(t2-t1); (1)

[0236] Wherein, Psmoothcharge is the first working power, SOCmax is the maximum charging capacity, SOC is the current battery state of charge, t2 is the end time point of the charging time period, and t1 is the time point corresponding to the current time information.

[0237] It can be understood that the first working power here is the working power that fully utilizes the charging time period to smoothly charge the battery module to the maximum charging capacity. The target working power when charging the battery module is determined according to the first working power, which can smoothly charge the battery module, and when the photovoltaic power generation surplus is insufficient, the battery module can be smoothly charged by taking power from the power grid.

[0238] The embodiment of the present application can smoothly charge the battery module, so that the battery module can always be fully charged at the end of the charging time period, and the battery charging efficiency is guaranteed.

[0239] In some embodiments of the present application, the acquisition module is also used to acquire the charging configuration information of the photovoltaic energy storage device when the current working mode is the charging mode. The determination module is also used to determine the first working power according to the grid power and the current working power of the battery module in the case that the charging configuration information is charging the battery module through the power grid, and the current battery state of charge is greater than or equal to the maximum charging capacity of the battery module, or in the case that the charging configuration information is not charging the battery module through the power grid. The target working power is determined according to the first working power.

[0240] In this embodiment, if the current working mode of the photovoltaic energy storage device is the charging mode, the charging configuration information allows charging through the power grid, but the current battery state of charge has reached or exceeded the maximum charging capacity, the battery module will not charge, and the first working power is determined according to the current working power of the battery module and the grid power.

[0241] If it is determined that the current working mode of the photovoltaic energy storage device is the charging mode, and the charging configuration information does not allow charging through the power grid, then at this time the photovoltaic energy storage device can only charge the battery module through the surplus power of the photovoltaic power generation module. It can be understood that the above-mentioned surplus power refers to the part of the power generated by the photovoltaic power generation module after deducting the part of the power directly used for power supply to the load, and at this time the first working power is determined according to the current working power of the battery module and the power grid power.

[0242] Exemplarily, the first working power is calculated by the following formula (2):

[0243] PObjabt1 = Pbat + Pgrid; (2)

[0244] Wherein, PObjabt1 is the first working power, Pbat is the current working power, and Pgrid is the power grid power.

[0245] Exemplarily, in the charging mode, the battery will not discharge externally, and after the current battery power of the battery module reaches the maximum charging power, the battery module will no longer be charged. At this time, the charging power of the battery module, that is, the current working power, is 0, and the power grid power is the data obtained by the power grid metering module. When the power grid is connected to the power grid and outputs the power supply, the power grid power is negative. When the power grid is connected to the power grid, the power grid power is positive.

[0246] For the case that the current battery power reaches the maximum charging power, if the power grid power is negative, the first working power is negative. The first working power being negative indicates that the battery module is charged according to the working power. However, since the battery module is full at this time, the actual target charging power is 0. If the power grid power is positive, the first working power is also positive. The first working power being positive indicates that the battery module is discharged according to the working power. However, since it is in the charging mode at this time, the battery module will not discharge externally, and therefore the actual target charging power is 0.

[0247] For the case that the battery module is not allowed to be charged through the power grid power, if the power grid power is negative, the first working power is negative. The first working power being negative indicates that the battery module is charged according to the working power. If the power grid power is positive, the first working power is positive. The first working power being positive indicates that the battery module is discharged according to the working power. However, since it is in the charging mode at this time, the battery module will not discharge externally, and therefore the actual target charging power is 0.

[0248] The embodiment of the present application can reasonably allocate the battery charging power according to the current battery power and whether the battery is allowed to be charged through the power grid, so as to realize the full utilization of photovoltaic power and improve the energy utilization rate of photovoltaic power generation.

[0249] In some embodiments of the present application, the determining module is further configured to, in the case that the current working mode is the non-charging mode, determine a first working power according to the grid power and the current working power of the battery module; and determine the target working power according to the first working power.

[0250] In this embodiment, if the current working mode of the photovoltaic energy storage device is the non-charging mode, the battery module can discharge to the outside to supply power to the load by the energy stored in the battery module when the condition is met, at this time, the first working power is determined according to the current working power of the battery module and the grid power. Exemplarily, the first working power is calculated by the above formula (2).

[0251] In the non-charging mode, the battery module can discharge to the outside, assuming that the battery module is in the discharging state, the current working power of the battery module is positive, and when the battery module is in the charging state, the current working power of the battery module is negative. Similarly, the grid power is negative when the photovoltaic energy storage device is connected to the grid to output power to the grid, and the grid power is positive when power is taken from the grid.

[0252] After calculation by formula (2), if the first working power is positive, the battery module is controlled to discharge according to the finally determined target working power, and if the first working power is negative, the battery module is controlled to charge according to the finally determined target working power.

[0253] The embodiment of the present application can dynamically adjust the target working power of the battery module to charge or discharge according to the grid power and the current working power of the battery module in the non-charging mode, which can effectively improve the energy utilization rate of photovoltaic power generation.

[0254] In some embodiments of the present application, the determining module is further configured to, in the case that the first working power is less than or equal to the maximum working power of the battery module, determine the first working power as the target working power; or in the case that the first working power is greater than the maximum working power of the battery module, determine the first threshold power as the target working power.

[0255] In this embodiment, the maximum working power of the battery module is the power threshold of the battery module when charging or discharging, and when the current working power of the battery module is greater than the maximum working power, it may cause problems such as battery heating, affecting the safety of power consumption.

[0256] Therefore, after the first working power is calculated, the greater one between the first working power and the maximum working power is taken as the target power of the battery.

[0257] For example, when the first working power is a charging power (a negative value) and the absolute value of the first working power is greater than the charging power threshold of the battery module (the absolute value of the maximum working power), the maximum working power of the battery module is set as the target working power, that is, the battery module is charged by the maximum charging power.

[0258] For example, when the first working power is a discharging power (a positive value) and the absolute value of the first working power is less than the discharging power threshold of the battery module (the absolute value of the maximum working power), the first working power is set as the target working power, that is, the battery module is controlled to supply power to the load by the first working power.

[0259] By selecting the larger one of the first working power and the maximum working power as the target working power, the embodiments of the present application can ensure the working safety of the battery module while ensuring the charging and discharging efficiency, and improve the reliability of the photovoltaic energy storage device.

[0260] In some embodiments of the present application, optionally, the current working mode includes a charging mode and a non-charging mode; the control module is further configured to control the photovoltaic energy storage device to charge the battery module according to the target working power when the current working mode is the charging mode and the current battery power is less than the maximum charging power, or control the photovoltaic energy storage device to supply power to the load according to the target working power when the current working mode is the non-charging mode and the current battery power is greater than the power threshold.

[0261] In this embodiment, in the charging mode, the photovoltaic energy storage device preferentially ensures the charging process of the battery module. At this time, if the current battery power does not reach the maximum charging power, that is, the battery module is not full, the battery module is charged by the determined target working power until the current battery power of the battery module is greater than or equal to the maximum charging power, and then the charging stops. At this time, the electric energy generated by the photovoltaic power generation module is entirely used for the load, or when there is a surplus after the electric energy generated by the photovoltaic power generation module is supplied to the load, the surplus electric energy is connected to the grid for power selling.

[0262] In the non-charging mode, the photovoltaic energy storage device can charge the battery module or supply power to the load by using the electric energy stored in the battery module. At this time, it is judged whether the battery power is greater than the power threshold. For example, the power threshold is a minimum power threshold when the battery module is discharged. When the current battery power of the battery module is less than the minimum power threshold, it indicates that the battery power is small. In order to avoid over-discharge or lockout of the battery, the battery module will not discharge externally at this time.

[0263] Therefore, when the photovoltaic energy storage device is in the non-charging mode and the current battery power of the battery module is greater than the power threshold, the battery module supplies power to the load when the photovoltaic power generated by the photovoltaic power generation cannot cover the entire power demand of the load, until the current battery power of the battery module is less than or equal to the power threshold, the battery module is controlled to stop discharging, and the battery module is charged when the condition allows.

[0264] The embodiment of the application can adaptively adjust the charging and discharging modes of the battery, avoid energy waste, and reduce the power taken from the power grid as much as possible to save electricity bills.

[0265] In some embodiments of the application, the photovoltaic energy storage device further comprises an energy storage conversion module and a photovoltaic inversion module; the determining module is further configured to determine the load power of the photovoltaic energy storage device according to the grid power, the inversion power of the energy storage conversion module, and the inversion power of the photovoltaic inversion module; determine the maximum inversion power of the energy storage conversion module according to the load power and the maximum feed-in power; wherein the maximum feed-in power is used to indicate the maximum power value of the photovoltaic energy storage device feeding into the grid.

[0266] The control of the photovoltaic energy storage device to perform the target operation according to the target working power comprises: controlling the photovoltaic energy storage device to perform the target operation according to the target working power and the maximum inversion power.

[0267] In this embodiment, the photovoltaic energy storage device comprises an energy storage conversion module (PCS), which exemplarily comprises a DC / AC bidirectional converter control unit and the like, wherein the control unit receives a background control instruction through a communication unit, controls the charging or discharging of the battery module according to the sign and size of the power instruction, and adjusts the active power and reactive power of the microgrid.

[0268] The photovoltaic inversion module is used to convert the direct current signal generated by the photovoltaic power generation into an alternating current signal to supply power to the load or sell electricity to the grid.

[0269] Exemplarily, during the operation of the photovoltaic energy storage device, the energy storage converter calculates the total load power according to the grid power, the inversion power of the energy storage conversion module, and the inversion power of the photovoltaic inversion module. Exemplarily, the load power can be calculated by the following formula (3):

[0270] Pload = Pgrid + Ppcs + Pacpv; (3)

[0271] Wherein, Pload is the load power, Pgrid is the grid power, Ppcs is the inversion power of the energy storage conversion module, and Pacpv is the inversion power of the photovoltaic inversion module.

[0272] After obtaining the load power, the maximum inverter power of the energy storage conversion module is calculated according to the load power and the maximum feeding power. For example, the maximum inverter power of the energy storage conversion module can be calculated by the following formula (4):

[0273] Ppcsmax = Pload + Pmaxsell - Pacpv (4)

[0274] Wherein, Ppcsmax is the maximum inverter power of the energy storage conversion module, Pload is the load power, Pacpv is the inverter power of the photovoltaic inverter module, Pmaxsell is the maximum feeding power, which is the maximum power of the photovoltaic energy storage device feeding the power grid, and Pmaxsell can be a fixed power value set in the program or a power value obtained by communicating with the upper device (such as a distribution box) of the power grid.

[0275] After obtaining the maximum inverter power of the energy storage conversion module, the maximum inverter power of the energy storage conversion module is used as the power instruction for controlling the working of the energy storage conversion module. By controlling the photovoltaic energy storage device to work through the power instruction, the active power and the reactive power can be accurately adjusted, and at the same time, the PCS can be kept in the range of the upper limit of the inverter power issued by the distribution box, and the inverter power is matched with the output power of the PV as much as possible, thereby improving the energy efficiency of the photovoltaic energy storage device.

[0276] In some embodiments of the present application, the control device further comprises an updating module for updating the target working power and the maximum inverter power; the control module is further configured to control the photovoltaic energy storage device to perform the target operation according to the updated target working power and the updated maximum inverter power when a preset condition is met; wherein the preset condition includes at least one of the following: the difference between the updated target working power and the previous target working power is greater than a power difference threshold, and the difference between the updated maximum inverter power and the previous maximum inverter power is greater than a power difference threshold.

[0277] In this embodiment, the photovoltaic energy storage device continuously updates the target working power and the maximum inverter power of the energy storage converter module during operation. When the difference between the updated target working power and the last issued target working power (the target working power before updating) is greater than the power difference threshold, or when the difference between the updated maximum inverter power and the last issued maximum inverter power (the maximum inverter power before updating) is greater than the power difference threshold, it indicates that the system load or the photovoltaic power generation condition has changed. At this time, the updated data is issued to the energy storage converter module PCS through the high-speed controller area network (CAN) bus, and the load and the like are recalculated according to the updated data to control the energy storage converter module PCS to adjust the power command and the charge-discharge power of the battery module.

[0278] When the difference between the updated target working power and the last issued target working power is not greater than the power difference threshold, and the difference between the updated maximum inverter power and the last issued maximum inverter power is not greater than the power difference threshold, it indicates that the system state has not changed greatly. At this time, the data change may come from the collection error or temporary fluctuation. The power adjustment command of the energy storage converter module PCS and the charge-discharge power of the battery module are maintained unchanged to avoid frequent adjustment of the system control parameters and ensure the stability of the system.

[0279] In some embodiments of the present application, a control device of a photovoltaic energy storage device is provided, Figure 5 The structure block diagram of the control device of the photovoltaic energy storage device of some embodiments of the present application is shown in FIG. 5. Figure 5 As shown in FIG. 5, the control device 500 includes a memory 502 for storing programs or instructions, and a processor 504 for executing the programs or instructions to realize the steps of the control method of the photovoltaic energy storage device provided in any of the above embodiments. Therefore, the control device 500 also includes all the beneficial effects of the control method of the photovoltaic energy storage device provided in any of the above embodiments. To avoid repetition, details are not described here.

[0280] In some embodiments of the present application, a readable storage medium is provided, which stores programs or instructions. When the programs or instructions are executed by a processor, the steps of the control method of the photovoltaic energy storage device provided in any of the above embodiments are realized. Therefore, the readable storage medium also includes all the beneficial effects of the control method of the photovoltaic energy storage device provided in any of the above embodiments. To avoid repetition, details are not described here.

[0281] In some embodiments of the present application, there is provided a photovoltaic energy storage device comprising the control device of the photovoltaic energy storage device as provided in any of the above embodiments, and / or the readable storage medium as provided in any of the above embodiments, thus comprising all the advantages of the control device of the photovoltaic energy storage device and the readable storage medium as provided in any of the above embodiments, which will not be repeated here for the sake of brevity.

[0282] The methods can be implemented in a variety of ways. For example, these methods can be implemented in hardware, firmware, and / or software. For example, in hardware implementations, a processor can be implemented within one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, micro-controllers, microprocessors, electronic devices, other devices units for performing the above-described functions, and / or combinations thereof.

[0283] The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium can be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, and any suitable combination of the foregoing. Computer readable storage media, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media, or electrical signals through a wire, digital or analog communication links, wireless communications links, and / or like.

[0284] In the description of the application, the term "a plurality" means two or more, unless otherwise expressly specified. The terms "upper", "lower", and the like, indicate the orientation or position relationship based on the drawings described in the application, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application. The terms "connected", "mounted", "fixed" and the like should be understood broadly, for example, "connected" can be fixed connection, can also be detachable connection, or integral connection; can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0285] In the description of the application, the terms "one embodiment", "some embodiments", "a specific embodiment" and the like described in the description of the application mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0286] The above is only the preferred embodiment of the application, and is not intended to limit the application. For those skilled in the art, the application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the application shall be included in the protection scope of the application.

Claims

1. A control method for a photovoltaic energy storage device, characterized in that, The photovoltaic energy storage device is electrically connected to the power grid and the load, the photovoltaic energy storage device includes a battery module, and the control method includes: Obtain grid power, the current battery level of the battery module, and the current time information; The current operating mode of the photovoltaic energy storage device is determined based on the current time information; Based on the current operating mode, the target operating power of the battery module is determined according to the grid power or the current battery charge. Based on the current operating mode, the photovoltaic energy storage device is controlled to perform target operations according to the target operating power; wherein, the target operations include: charging the battery module and supplying power to the load through the battery module.

2. The control method according to claim 1, characterized in that, Determining the current operating mode of the photovoltaic energy storage device based on the current time information includes: If the current time information falls within a charging period, the current operating mode is determined to be the charging mode; or If the current time information is outside the charging time period, the current working mode is determined to be a non-charging mode.

3. The control method according to claim 2, characterized in that, The step of determining the target operating power of the battery module based on the current operating mode, according to the grid power or the current battery charge, includes: When the current working mode is the charging mode, obtain the charging configuration information of the photovoltaic energy storage device; When the charging configuration information indicates that the battery module is charged through the power grid, and the current battery capacity is less than the maximum charging capacity of the battery module, the first operating power is determined based on the maximum charging capacity, the current battery capacity, the charging time period, and the current time information. The target operating power is determined based on the first operating power.

4. The control method according to claim 2, characterized in that, The step of determining the target operating power of the battery module based on the current operating mode, according to the grid power or the current battery charge, includes: When the current working mode is the charging mode, obtain the charging configuration information of the photovoltaic energy storage device; When the charging configuration information indicates that the battery module is charged through the power grid and the current battery capacity is greater than or equal to the maximum charging capacity of the battery module, or when the charging configuration information indicates that the battery module is not charged through the power grid, a first operating power is determined based on the power grid power and the current operating power of the battery module. The target operating power is determined based on the first operating power.

5. The control method according to claim 2, characterized in that, The step of determining the target operating power of the battery module based on the current operating mode, according to the grid power or the current battery charge, includes: When the current operating mode is the non-charging mode, a first operating power is determined based on the grid power and the current operating power of the battery module; The target operating power is determined based on the first operating power.

6. The control method according to any one of claims 3 to 5, characterized in that, Determining the target operating power based on the first operating power includes: If the first operating power is less than or equal to the maximum operating power of the battery module, the first operating power is determined as the target operating power; or If the first operating power is greater than the maximum operating power of the battery module, the maximum operating power is determined as the target operating power.

7. The control method according to any one of claims 1 to 5, characterized in that, The current operating mode includes a charging mode and a non-charging mode; the step of controlling the photovoltaic energy storage device to perform target operations according to the target operating power based on the current operating mode includes: When the current operating mode is the charging mode and the current battery level is less than the maximum charging level, the photovoltaic energy storage device is controlled to charge the battery module according to the target operating power; or When the current operating mode is non-charging mode and the current battery level is greater than the power threshold, the photovoltaic energy storage device is controlled to supply power to the load according to the target operating power.

8. The control method according to any one of claims 1 to 5, characterized in that, The photovoltaic energy storage device also includes an energy storage converter module and a photovoltaic inverter module; Before determining the target operating power of the battery module based on the grid power or the current battery charge, the control method further includes: The load power of the photovoltaic energy storage device is determined based on the grid power, the inverter power of the energy storage converter module, and the inverter power of the photovoltaic inverter module. The maximum inverter power of the energy storage converter module is determined based on the maximum load power and the maximum feed power; wherein, the maximum feed power is used to indicate the maximum power value that the photovoltaic energy storage device feeds to the grid; The control of the photovoltaic energy storage device to perform target operations according to the target operating power includes: The photovoltaic energy storage device is controlled to perform the target operation based on the target operating power and the maximum value of the inverter power.

9. The control method according to claim 8, characterized in that, After controlling the photovoltaic energy storage device to perform the target operation based on the target operating power and the maximum inverter power, the control method further includes: Update the target operating power and the maximum inverter power; Under preset conditions, the photovoltaic energy storage device is controlled to perform the target operation based on the updated target operating power and the updated maximum inverter power. The preset conditions include at least one of the following: the difference between the updated target operating power and the original target operating power is greater than a power difference threshold, and the difference between the updated maximum inverter power and the original maximum inverter power is greater than the power difference threshold.

10. A control device for a photovoltaic energy storage device, characterized in that, The photovoltaic energy storage device is electrically connected to the power grid and the load, the photovoltaic energy storage device includes a battery module, and the control device includes: The acquisition module is used to acquire grid power, the current battery level of the battery module, and the current time information; The determination module is used to determine the current operating mode of the photovoltaic energy storage device based on the current time information; and Based on the current operating mode, the target operating power of the battery module is determined according to the grid power or the current battery charge. The control module is used to control the photovoltaic energy storage device to perform target operations according to the target operating power based on the current operating mode; wherein the target operations include: charging the battery module and supplying power to the load through the battery module.

11. A control device for a photovoltaic energy storage device, characterized in that, The control device includes: Memory, used to store programs or instructions; A processor is configured to implement the steps of the control method for a photovoltaic energy storage device as described in any one of claims 1 to 9 when executing the program or instructions.

12. A readable storage medium having a program or instructions stored thereon, characterized in that, When the program or instructions are executed by the processor, they implement the steps of the control method for the photovoltaic energy storage device as described in any one of claims 1 to 9.

13. A photovoltaic energy storage device, characterized in that, include: The control device for the photovoltaic energy storage equipment as described in claim 10 or 11; and / or The readable storage medium as described in claim 12.

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