Energy storage control method, photovoltaic heat pump system, and device and storage medium

Abstract

An energy storage control method, a photovoltaic heat pump system, and a device and a storage medium. The method is applied to a photovoltaic heat pump system, wherein the photovoltaic heat pump system comprises a photovoltaic device, a heat pump device, and a heat storage water tank in communication with the heat pump device. The energy storage control method comprises: in a photovoltaic thermal charging mode, periodically executing the following processing: on the basis of the difference between a current available photovoltaic thermal charging power and a current heat pump operation power, adjusting a set water output temperature so as to adjust the heat pump operation power, such that the heat pump operation power can change along with a change in the available photovoltaic thermal charging power in a positively correlated manner.

Description

Energy storage control method, photovoltaic heat pump system, device and storage medium Technical Field

[0001] The present application relates to photovoltaic heat pump control technology, and in particular to an energy storage control method, a photovoltaic heat pump system, equipment, and storage medium. Background Art

[0002] In photovoltaic energy storage systems, when photovoltaics are used to power the heat pump, in a photovoltaic-heat pump linkage solution, the photovoltaic power is often stored in batteries, which are then used to power the heat pump. Alternatively, if the photovoltaic power generation is high, the photovoltaic power is directly used to power the heat pump through an inverter. However, to maintain stable heat pump operation, it is necessary to switch to the mains when the photovoltaic power generation is insufficient. Some feasible photovoltaic power supply methods for heat pumps result in wasteful photovoltaic power generation due to the instability of photovoltaic power generation and heat pump operating power. To maximize the use of photovoltaic power to power the heat pump, improve household energy self-sufficiency and photovoltaic power self-consumption rate, and reduce electricity purchases, it is necessary to continuously optimize the control scheme of the photovoltaic energy storage system. Summary of the Invention

[0003] This application provides an energy storage control method, photovoltaic heat pump system, device, and storage medium for a photovoltaic heat pump system. By adjusting the outlet water setpoint temperature to regulate the heat pump's operating power in photovoltaic heating mode, the heat pump's real-time operating power varies with photovoltaic power generation. This ensures that photovoltaic power can maintain power to the heat pump even when photovoltaic power generation fluctuates within a certain range, maintaining overall system operational stability.

[0004] The present application provides an energy storage control method, which is applied to a photovoltaic heat pump system. The photovoltaic heat pump system includes a photovoltaic device, a heat pump device, and a hot water storage tank connected to the heat pump device. The energy storage control method includes:

[0005] In the photovoltaic thermal charging mode, the following processes are performed periodically:

[0006] According to the difference between the current available photovoltaic charging power and the current heat pump operating power, the outlet water set temperature is adjusted to adjust the heat pump operating power, so that the heat pump operating power can change in a positively correlated manner with the change in the available photovoltaic charging power;

[0007] The available photovoltaic heating power is the power of the photovoltaic power generation that can be used to supply power to the heat pump to heat the hot water storage tank.

[0008] The present application also provides a photovoltaic heat pump system, comprising:

[0009] a control device, a photovoltaic device and a heat pump device electrically connected to the control device, and a hot water storage tank in communication with the heat pump device;

[0010] Wherein, the control device is configured to execute the energy storage control method as described in any embodiment of the present disclosure.

[0011] The present application also provides an electronic device, comprising:

[0012] one or more processors;

[0013] a storage device for storing one or more programs,

[0014] When the one or more programs are executed by the one or more processors, the one or more processors implement the energy storage control method as described in any embodiment of the present disclosure.

[0015] The present application also provides a computer storage medium, in which a computer program is stored. The computer program is configured to execute the energy storage control method as described in any embodiment of the present disclosure when running.

[0016] Compared with the related art, the present application adjusts the outlet water set temperature to adjust the heat pump operating power according to the difference between the current available photovoltaic heating power and the current heat pump operating power, so that the heat pump operating power can change in a positively correlated manner with the change of the available photovoltaic heating power, which can effectively control the operating stability of the photovoltaic heating mode and maximize the utilization of the available photovoltaic heating power, thereby improving the overall system efficiency.

[0017] Other features and advantages of the present application will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present application. Other advantages of the present application can be realized and obtained by the solutions described in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide an understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0019] Figure 1 is a schematic diagram of a solar thermal storage and flexible system in a feasible solution;

[0020] FIG2 is a schematic diagram of heat pump heat storage in an achievable solution;

[0021] FIG3 is a flow chart of an energy storage control method provided in an embodiment of the present application;

[0022] FIG4 is a flow chart of another energy storage control method provided in an embodiment of the present application;

[0023] FIG5 is a flow chart of another energy storage control method provided in an embodiment of the present application;

[0024] FIG6 is a structural diagram of a photovoltaic heat pump system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] This application describes multiple embodiments, but this description is exemplary rather than restrictive, and it will be apparent to those skilled in the art that there may be more embodiments and implementations within the scope of the embodiments described herein. Although many possible feature combinations are shown in the drawings and discussed in the detailed description, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with any other feature or element in any other embodiment, or may replace any other feature or element in any other embodiment.

[0026] This application includes and contemplates combinations of features and elements known to those of ordinary skill in the art. The embodiments, features, and elements disclosed in this application may also be combined with any conventional features or elements to form a unique inventive solution defined by the claims. Any features or elements of any embodiment may also be combined with features or elements from other inventive solutions to form another unique inventive solution defined by the claims. Therefore, it should be understood that any feature shown and / or discussed in this application may be implemented individually or in any appropriate combination. Therefore, except for the limitations made according to the appended claims and their equivalents, the embodiments are not subject to other limitations. In addition, various modifications and changes may be made within the scope of protection of the appended claims.

[0027] In addition, when describing representative embodiments, the specification may have presented the method and / or process as a specific sequence of steps. However, to the extent that the method or process does not rely on the specific order of the steps described herein, the method or process should not be limited to the steps in the specific order described. As will be understood by those skilled in the art, other orders of steps are also possible. Therefore, the specific order of the steps set forth in the specification should not be interpreted as a limitation to the claims. In addition, the claims for the method and / or process should not be limited to performing their steps in the order written, and those skilled in the art can readily understand that these orders can be changed and still remain within the spirit and scope of the embodiments of the present application.

[0028] Some feasible photovoltaic heat pump systems, such as the photovoltaic heat storage and flexible system, include two major components: an energy storage system centered around an inverter and batteries, and a heat storage system centered around a heat pump and a hot water storage tank. For example, as shown in Figure 1, the photovoltaic heat storage and flexible system includes photovoltaic panels, batteries, an ESP (Emergency Standby Power, generally not connected to a load), a heat pump and a hot water storage tank, and other loads. The grid is connected to the inverter to provide power when needed. During periods of high electricity prices, when photovoltaic power generation is insufficient, energy is discharged (battery discharge and water tank heating); when photovoltaic power generation is sufficient, photovoltaic power is prioritized for storage, and heat is stored after the battery is fully charged. During periods of off-peak electricity prices, the grid is used as a power source for both electricity and heat storage.

[0029] Figure 2 shows some feasible heat pump thermal storage solutions. The heat pump system consists of a hydraulic module connected to a heat storage tank. Heat pump thermal storage involves heating the water in the tank to store heat. During heat pump heating, the refrigerant exits the compressor, passes through a four-way valve, and then enters the plate heat exchanger for convection heat exchange with the water. This heats the water in the hydraulic module before returning to the compressor through a finned heat exchanger (in this case, the evaporator).

[0030] It should be noted that heat pumps can provide both heating and cooling, and this application does not address heat pump cooling. Upon startup, the heat pump of a photovoltaic heat pump system enters an initial operating mode. When photovoltaic heat charging conditions are met, the system enters photovoltaic heat charging mode, heating the hot water storage tank and storing heat. It is understood that photovoltaic heat charging mode utilizes photovoltaic power generation to directly supply heat to the heat pump to charge the hot water storage tank. In some exemplary embodiments, after startup, if the heat pump does not enter photovoltaic heat charging mode, it may enter grid heat charging mode based on the system's operational control strategy.

[0031] In a photovoltaic heat pump system, photovoltaic power generation is significantly affected by environmental factors. When photovoltaic power generation is used to power a heat pump for heating, if a fixed operating power is used for heating, then due to fluctuations in photovoltaic power generation, the current power generation will not meet the heat pump operating power requirements, and charging will be terminated or supplemented by mains power. When there is more available power reserve, photovoltaic power generation will be wasted. The present application provides an energy storage control method that dynamically adjusts the heat pump operating power in photovoltaic heating mode according to the actual power of photovoltaic power generation, ensuring that photovoltaic power can be used to power the heat pump even when the photovoltaic power generation fluctuates within a certain range. This method can maximize the use of photovoltaic power generation, reduce the amount of electricity purchased, and maintain the stability of the heating mode operation.

[0032] An embodiment of the present disclosure provides an energy storage control method, which is applied to a photovoltaic heat pump system. The photovoltaic heat pump system includes a photovoltaic device, a heat pump device, and a hot water storage tank connected to the heat pump device. As shown in FIG3 , the energy storage control method includes:

[0033] In the photovoltaic thermal charging mode, the following processes are performed periodically:

[0034] Step 310: Adjust the outlet water set temperature to adjust the heat pump operating power based on the difference between the current available photovoltaic heating power and the current heat pump operating power, so that the heat pump operating power can change in a positively correlated manner with the change in the available photovoltaic heating power.

[0035] The available photovoltaic heating power is the power of the photovoltaic power generation that can be used to supply power to the heat pump to heat the hot water storage tank.

[0036] It should be noted that, as shown in Figure 1, the photovoltaic energy storage system includes not only a heat pump but also batteries and other loads; alternatively, the photovoltaic energy storage system includes not only a heat pump but other loads but no batteries. Other loads operate using photovoltaic power, such as lighting systems, production systems, and air purification systems. In some implementations, photovoltaic power generation first meets the basic operating needs of all loads. If batteries are available, this power supply is met for all loads, and battery charging is prioritized. After the batteries are fully charged and there is still power generation capacity available, the system enters photovoltaic heating mode. In some implementations, photovoltaic power generation first meets the operating needs of all loads. If batteries are not available, this power supply is met, and the system enters photovoltaic heating mode. In addition to charging the heat storage tank, the heat pump can also connect to end-user devices to provide heating and hot water. The embodiments of this disclosure only cover the heat pump's heating mode. After the heat pump is started and does not enter heating mode, it does not charge the heat storage tank and only provides heat to the connected end-user devices. The heat pump itself can also connect to end-user devices for cooling, but this aspect is not discussed in detail in this application. Among them, when the heat pump is in non-heating mode and provides heating for the terminal equipment, the total load includes other loads and heat pump load.

[0037] Available PV thermal charging power refers to the amount of PV generated power available to heat the hot water storage tank while meeting the needs of other loads. The actual power used for thermal charging falls within this available range. In PV thermal charging mode, the heat pump operates to heat the hot water storage tank, or to heat the hot water storage tank and provide heating to terminal equipment.

[0038] It can be understood that when photovoltaic power is supplied, the photovoltaic energy storage system can operate in load power supply mode, charging + load power supply mode, or heating + load power supply mode. For photovoltaic energy storage systems, supplying power to related loads is a basic system function. Therefore, the heating + load power supply mode is also called photovoltaic heating mode. In addition to supplying power to the electrical load, photovoltaic power generation also heats the hot water storage tank.

[0039] In some exemplary embodiments, the currently available photovoltaic thermal power P_hot=the current photovoltaic power generation power P_power−the other load power P_other.

[0040] The current heat pump operating power P_real, that is, the actual power of the heat pump operation, in the heat pump charging mode, the heat pump operation can heat the hot water tank, or it can heat the hot water tank and heat the terminal equipment.

[0041] The difference between the current available PV heating power and the current heat pump operating power (P_surplus) is calculated as: the current available PV heating power (P_hot) - the current heat pump operating power (P_real), i.e., P_surplus = P_power - P_other - P_real. As you can see, if this difference is greater than 0, less than 0, or equal to 0, a positive temperature increment indicates a temperature increase, a negative temperature increment indicates a temperature decrease, or the temperature remains unchanged.

[0042] It should be noted that the heat pump device shown includes a hydraulic module. The heat pump's outlet water setpoint temperature refers to the setpoint temperature at the water outlet of the heat pump hydraulic module. Controlling this outlet water setpoint temperature can regulate the heat pump's operating power. Adjusting the outlet water setpoint temperature based on the difference between the currently available photovoltaic heating power and the current heat pump operating power can adjust the heat pump's operating power. Increasing the outlet water setpoint temperature increases the heat pump's operating power, while decreasing the outlet water setpoint temperature decreases the heat pump's operating power.

[0043] It can be understood that according to the solution provided in the embodiment of the present disclosure, in the photovoltaic heating mode, the outlet water set temperature is adjusted to adjust the heat pump operating power, so that the heat pump operating power can change in a positively correlated manner with the change of the available photovoltaic heating power, which means that by adjusting the outlet water set temperature, when the available photovoltaic heating power increases, the heat pump operating power is increased, and when the available photovoltaic heating power decreases, the heat pump operating power is reduced, thereby realizing dynamic adjustment of the heat pump heating according to the fluctuation of photovoltaic power generation, maintaining the stability of the heating mode, and making full use of the available heating photovoltaic power.

[0044] In some exemplary embodiments, adjusting the outlet water set temperature to adjust the heat pump operating power based on the difference between the current available photovoltaic heating power and the current heat pump operating power includes:

[0045] selecting an available temperature increment, and if selected, determining a target outlet water set temperature based on the selected temperature increment; and adjusting the current outlet water set temperature to the determined target outlet water set temperature;

[0046] The step of determining the target outlet water setting temperature based on the selected temperature increment includes: performing the following judgment on the selected temperature increment: adding the temperature increment to the current outlet water setting temperature to obtain a candidate outlet water setting temperature, and determining the expected heat pump operating power at the candidate outlet water setting temperature; judging whether the currently available photovoltaic heating power and the expected heat pump operating power meet a preset adjustment condition, and if so, determining the candidate outlet water setting temperature as the target outlet water setting temperature;

[0047] The available temperature increment has the same sign as the difference, and the candidate outlet water setting temperature obtained by adding the available temperature increment to the current outlet water setting temperature is within an allowable outlet water setting temperature range.

[0048] In some exemplary embodiments, when the difference is positive and multiple temperature increments are selected, the judgment is performed one by one on the selected multiple temperature increments in descending order until the target water outlet set temperature is determined. If the judgment has been performed on all selected temperature increments but the target water outlet set temperature has not been determined, the current water outlet set temperature is determined as the target water outlet set temperature.

[0049] It can be understood that when the difference is positive and multiple temperature increments are selected, the candidate outlet water setting temperatures are judged one by one in descending order of temperature increments, that is, in descending order of candidate outlet water setting temperatures. If it is judged that the preset adjustment conditions are met, the target outlet water setting temperature is determined and adjusted, and the judgment of subsequent candidate outlet water setting temperatures is no longer continued. If all candidate outlet water setting temperatures do not meet the preset adjustment conditions, the current outlet water setting temperature is determined as the target outlet water setting temperature, that is, the current outlet water setting temperature is not adjusted in this cycle. If the difference is negative, it means that the temperature is judged by gradually decreasing from the highest available temperature in descending order of temperature increments, and finally the highest temperature that meets the preset adjustment conditions is determined, which can maximize the use of available photovoltaic heating power for heating.

[0050] In some exemplary embodiments, when the difference is negative and multiple temperature increments are selected, the judgment is performed one by one on the selected multiple temperature increments in descending order until the target water outlet set temperature is determined. If the judgment has been performed on all selected temperature increments but the target water outlet set temperature has not been determined, the photovoltaic heating mode is exited.

[0051] It is understood that if the difference is negative and multiple temperature increments are selected, the candidate outlet water set temperatures are judged one by one in descending order of temperature increments. If it is determined that the preset adjustment conditions are met, the target outlet water set temperature is determined and adjusted, and the judgment of subsequent candidate outlet water set temperatures is discontinued. If all candidate outlet water set temperatures do not meet the preset adjustment conditions, the photovoltaic heating mode is exited. If the difference is negative, the temperature increments are ordered from large to small, indicating that the temperature is gradually lowered from the current outlet water set temperature, and the highest temperature that meets the preset adjustment conditions is finally determined, which can maximize the use of available photovoltaic heating power for heating.

[0052] In some exemplary embodiments, adjusting the outlet water set temperature to adjust the heat pump operating power based on the difference between the current available photovoltaic heating power and the current heat pump operating power includes:

[0053] Select an available temperature increment. If selected, perform the following temperature adjustment process based on the selected temperature increments one by one until the target outlet water set temperature for this cycle is determined and all temperature increments are adjusted or completed:

[0054] Adding the temperature increment to the current outlet water set temperature obtains a candidate target outlet water set temperature corresponding to the temperature increment, and determines the expected heat pump operating power at the candidate outlet water set temperature;

[0055] Determine whether the currently available photovoltaic heating power and the expected heat pump operating power meet the preset adjustment conditions:

[0056] When the preset adjustment conditions are met, the target outlet water setting temperature of this cycle is determined to be the candidate outlet water setting temperature, and the outlet water setting temperature is adjusted to the target outlet water setting temperature;

[0057] When the preset adjustment condition is not met, the temperature adjustment process based on the temperature increment is terminated;

[0058] The available temperature increment has the same sign as the difference, and the target outlet water setting temperature corresponding to the available temperature increment is within an allowable outlet water setting temperature range.

[0059] It can be understood that the candidate outlet water set temperature corresponding to the temperature increment is within the allowable outlet water set temperature range, which means that the current outlet water set temperature + the temperature increment is within the allowable outlet water set temperature range of the heat pump. For example, if the allowable outlet water set temperature range is 30-70 degrees Celsius and the current outlet water set temperature is 67 degrees Celsius, the maximum available temperature increment is +3 and the minimum available temperature increment is -37. One or more available temperature increments can be selected.

[0060] In some exemplary embodiments, when n available temperature increments Δt1, Δt2, ..., Δtn are selected and 0<Δt1<Δt2< ...<Δtn, temperature adjustment processing is performed one by one based on Δtn, Δtn-1, ...Δt1 in sequence, 1≤n≤N, where N is the maximum number of temperature increments allowed to be selected when the difference is positive;

[0061] When the temperature adjustment process based on n available temperature increments is completed but the target outlet water set temperature of this cycle has not yet been determined and adjusted, the current outlet water set temperature is kept unchanged.

[0062] For example, N=2, n=2, select two available temperature increments, Δt1=+1, Δt2=+2, and the current outlet set temperature is T. Then, the temperature adjustment process is performed based on Δt2=+2 and Δt1=+1, including:

[0063] Δt2=+2, candidate outlet water set temperature=T+2, determine the expected heat pump operating power P_predict at this temperature, and judge whether the currently available photovoltaic heating power P_hot and the expected heat pump operating power P_predict meet the preset adjustment conditions. If so, determine the target outlet water set temperature for this cycle as T+2, and adjust the outlet water set temperature to T+2, completing the adjustment of the outlet water set temperature for this cycle; if not, end the temperature adjustment process for the temperature increment +2 and continue the temperature adjustment process for the next temperature increment;

[0064] Δt2=+1, candidate outlet water set temperature=T+1, determine the expected heat pump operating power P_predict at this temperature, and judge whether the current available photovoltaic heating power P_hot and the expected heat pump operating power P_predict meet the preset adjustment conditions. If so, determine the target outlet water set temperature for this cycle as T+1, and adjust the outlet water set temperature to T+1, completing the adjustment of the outlet water set temperature for this cycle; if not, end the temperature adjustment process of the temperature increment +1;

[0065] If it is not satisfied, after the temperature adjustment process of temperature increment + 1 is completed, there is no next temperature increment, and the temperature adjustment process of all 2 temperature increments is completed, but the target water outlet set temperature of this cycle is not determined and adjusted, then the current water outlet set temperature remains unchanged.

[0066] It can be seen that when the temperature increment is positive, the n available temperature increments selected are all greater than 0, and the corresponding temperature adjustment processing is performed starting from the largest temperature increment. If the candidate outlet water set temperature is determined as the target outlet water set temperature and adjusted, the heat pump operating power adjustment of this cycle is completed, and the temperature adjustment processing corresponding to the subsequent temperature increments is no longer performed.

[0067] In some exemplary embodiments, when m available temperature increments Δt1, Δt2, ..., Δtm are selected and Δt1<Δt2< ...<Δtm<0, temperature adjustment processing is performed one by one based on Δtm, Δtm-1, ...Δt1 in sequence, 1≤m≤M, where M is the maximum number of temperature increments allowed to be selected when the difference is negative;

[0068] When the temperature adjustment process based on m available temperature increments is completed but the target outlet water set temperature of this cycle has not yet been determined and adjusted, the photovoltaic thermal charging mode is exited.

[0069] For example, M=3, m=3, select 3 available temperature increments, Δt1=-3, Δt2=-2, Δt3=-1. The current outlet set temperature is T. Then, the temperature adjustment process is performed based on Δt3=-1, Δt2=-2, and Δt1=-3 in sequence, including:

[0070] Δt3 = -1, candidate outlet water set temperature = T-1, determine the expected heat pump operating power P_predict at this temperature, and judge whether the currently available photovoltaic heating power P_hot and the expected heat pump operating power P_predict meet the preset adjustment conditions. If so, determine the target outlet water set temperature for this cycle as T-1, and adjust the outlet water set temperature to T-1, completing the adjustment of the outlet water set temperature for this cycle; if not, end the temperature adjustment process for the temperature increment -1 and continue the temperature adjustment process for the next temperature increment;

[0071] Δt2 = -2, candidate outlet water set temperature = T-2, determine the expected heat pump operating power P_predict at this temperature, and judge whether the currently available photovoltaic heating power P_hot and the expected heat pump operating power P_predict meet the preset adjustment conditions. If so, determine the target outlet water set temperature for this cycle as T-2, and adjust the outlet water set temperature to T-2, completing the adjustment of the outlet water set temperature for this cycle; if not, end the temperature adjustment process for the temperature increment -2;

[0072] Δt3 = -1, candidate outlet water set temperature = T-3, determine the expected heat pump operating power P_predict at this temperature, and judge whether the currently available photovoltaic heating power P_hot and the expected heat pump operating power P_predict meet the preset adjustment conditions. If so, determine the target outlet water set temperature for this cycle as T-3, and adjust the outlet water set temperature to T-2, completing the adjustment of the outlet water set temperature for this cycle; if not, end the temperature adjustment process of the temperature increment -3;

[0073] It can be seen that if it is not satisfied, after the temperature adjustment process of temperature increment -3 is completed, there is no next temperature increment, and the temperature adjustment process of all 3 temperature increments is completed, but the target water outlet set temperature of this cycle is not determined and adjusted, then the photovoltaic heating mode is exited.

[0074] In some exemplary embodiments, determining whether the currently available photovoltaic heating power and the expected heat pump operating power meet a preset adjustment condition includes:

[0075] When the available temperature increment is positive, determining whether the currently available photovoltaic charging power is greater than a first ratio of the expected heat pump operating power, the first ratio being greater than 1;

[0076] When the available temperature increment is negative, it is determined whether the currently available photovoltaic thermal charging power is greater than a second ratio of the expected heat pump operating power, the second ratio being less than 1.

[0077] When the available temperature increment is positive, if it is determined that the currently available photovoltaic heating power is greater than the first ratio of the expected heat pump operating power, the preset adjustment condition is met; if the currently available photovoltaic heating power is less than or equal to the first ratio of the expected heat pump operating power, the preset adjustment condition is not met.

[0078] When the available temperature increment is negative, if it is determined that the currently available photovoltaic heating power is greater than the second ratio of the expected heat pump operating power, the preset adjustment condition is met; if the currently available photovoltaic heating power is less than or equal to the second ratio of the expected heat pump operating power, the preset adjustment condition is not met.

[0079] For example, the first ratio is 1.25. When the available increment is positive, the current available photovoltaic heating power P_hot = P_power-P_other, and the expected heat pump operating power P_predict. When P_hot>1.25*P_predict, the adjustment condition is met, and the candidate outlet water setting temperature corresponding to the available increment is determined as the target outlet water setting temperature and adjusted accordingly, completing the temperature adjustment processing of this cycle.

[0080] The second ratio is 0.83. When the available increment is negative, the current available photovoltaic heating power P_hot = P_power - P_other, and the expected heat pump operating power P_predict. When P_hot>0.83*P_predict, the adjustment condition is met, and the candidate outlet water set temperature corresponding to the available increment is determined as the target outlet water set temperature and adjusted accordingly, completing the temperature adjustment process of this cycle.

[0081] In some exemplary embodiments, available temperature increments are selected, including:

[0082] Select one or more available temperature increments from a preset range.

[0083] For example, the preset range includes: -1, -2; or the preset range includes: +1, +2, +3. More examples are not listed here one by one, and the preset range can be set in advance.

[0084] In some exemplary embodiments, adjusting the outlet water set temperature to adjust the heat pump operating power based on the difference between the current available photovoltaic heating power and the current heat pump operating power may further include any one or more of the following:

[0085] When the current outlet water set temperature is the upper limit temperature and the sign of the difference is positive, the current outlet water set temperature is maintained unchanged or the photovoltaic heating mode is exited;

[0086] When the current outlet water set temperature is the lower limit temperature and the difference sign is negative, when the ratio of the current available photovoltaic heating power to the current heat pump operating power is greater than or equal to the preset minimum ratio, the current outlet water set temperature is maintained unchanged; when the ratio of the current available photovoltaic heating power to the current heat pump operating power is less than the preset minimum ratio, the photovoltaic heating mode is exited;

[0087] The current temperature of the hot water storage tank is obtained, and when the current temperature of the hot water storage tank reaches the upper limit temperature of the hot water storage tank and the sign of the difference is positive, the photovoltaic thermal charging mode is exited.

[0088] If the current outlet water set temperature is the upper limit temperature and the difference sign is positive, it means that the current outlet water set temperature has reached the set upper limit temperature and cannot be further increased, and the current outlet water set temperature will be maintained unchanged. If the current outlet water set temperature is the lower limit temperature and the difference sign is negative, it means that the current outlet water set temperature has reached the set lower limit temperature and cannot be further decreased. If the ratio of the current available photovoltaic charging power to the current heat pump operating power is greater than or equal to the preset minimum ratio, the current outlet water set temperature will be maintained unchanged. If the current outlet water set temperature is the lower limit temperature and the difference sign is negative, it means that the current outlet water set temperature has reached the set lower limit temperature and cannot be further decreased. If the ratio of the current available photovoltaic charging power to the current heat pump operating power is less than the preset minimum ratio, the photovoltaic charging mode will be exited.

[0089] When the current temperature of the hot water storage tank reaches the upper limit temperature of the hot water storage tank and the difference sign is positive, it means that the current hot water storage tank has reached the upper limit temperature for heat storage and cannot continue to rise, and the photovoltaic heat charging mode is exited.

[0090] In some exemplary embodiments, the upper limit temperature at which the hot water storage tank can store heat is the same as the upper limit temperature of the water outlet setting temperature of the hydraulic module.

[0091] In some exemplary embodiments, when the sign of the difference is positive, if the current outlet water set temperature is the upper limit temperature, indicating that the current outlet water set temperature has reached the set upper limit temperature, the photovoltaic thermal charging mode is exited when the current temperature of the hot water storage tank is determined to have reached the upper limit temperature; if the current temperature of the hot water storage tank is determined to have not reached the upper limit temperature, the current outlet water set temperature is maintained. It is understood that when the current outlet water set temperature is the upper limit temperature, if the actual temperature of the hot water storage tank is detected as the upper limit temperature / current temperature and it also reaches the upper limit temperature, it means that the water temperature in the hot water storage tank will not rise further, and the photovoltaic thermal charging mode can be exited.

[0092] In some exemplary embodiments, as shown in FIG4 , the method further includes:

[0093] Step 300: When it is determined that the heat pump charging condition is met based on the difference between the currently available photovoltaic heating power and the rated heating power of the heat pump device, the photovoltaic heat pump system starts to operate in the photovoltaic heating mode.

[0094] In some exemplary embodiments, in step 300 , when the difference is greater than a third ratio of the rated heating power of the heat pump device, it is determined that the heat pump charging condition is met, and the third ratio is less than 1.

[0095] For example, the third ratio = 20%. The difference between the currently available photovoltaic heating power and the rated heating power of the heat pump device, P_surplus_start, equals the currently available photovoltaic heating power, P_hot, minus the rated heating power, P_rated, of the heat pump device. That is, when P_surplus_start > 20% * P_rated, the heat pump heating condition is determined to be met, and the photovoltaic heating mode is entered. Wherein, the currently available photovoltaic heating power, P_hot, equals P_power - P_other, i.e., P_power - P_other - P_rated > 20% * P_rated, and the heat pump heating condition is determined to be met, and the photovoltaic heating mode is entered.

[0096] In some exemplary embodiments, in step 300, when the difference is greater than a third ratio of the rated heating power of the heat pump device and the battery in the photovoltaic heat pump system is fully charged, it is determined that the heat pump charging condition is met, and the third ratio is less than 1.

[0097] In some exemplary embodiments, the expected heat pump operating power at the candidate outlet water set temperature is determined according to one of the following methods:

[0098] Determining the heat pump operating power using a heat pump power prediction model based on the candidate outlet water temperature and the current outdoor ambient temperature;

[0099] The heat pump operating power is determined by looking up a preset heat pump operating power lookup table according to the candidate outlet water temperature and the current outdoor ambient temperature.

[0100] In some exemplary embodiments, the heat pump power prediction model is obtained by fitting the historical operating data of the heat pump equipment;

[0101] The historical operating condition data includes multiple sets of data collected within the most recent set period of time, and each set of data includes the outlet water set temperature, the outdoor ambient temperature and the heat pump operating power.

[0102] In some exemplary embodiments, the heat pump power prediction model is the following function:

[0103] Among them, P is the heat pump operating power, TempSetting is the target water outlet temperature, T E is the outdoor ambient temperature, K1, K2, K3, b2, b3 are model parameters, and T1 is the preset temperature value.

[0104] For example, T1 = -10. It will be appreciated that in some exemplary implementations, for a given heat pump model, T1 = -10 is a set temperature value selected based on fitting of measured operating data. The relevant variation patterns differ when the ambient temperature is less than -10 degrees Celsius and when it is greater than or equal to -10 degrees Celsius. For different heat pumps, the set temperature may be determined based on fitting of measured operating data, and is not limited to the exemplary aspects of this disclosure.

[0105] In some exemplary embodiments, the outlet water setting temperature TempSetting and the heat pump operating power P satisfy the functional relationship P = K1 * TempSetting + b, then b and the outdoor ambient temperature T are determined by fitting based on historical operating data. E The relationship is as follows:

[0106] In some exemplary embodiments, the method further includes: collecting and saving operating condition data according to set collection rules.

[0107] In some exemplary embodiments, the method further comprises:

[0108] According to the set model update time plan, the heat pump power prediction model is updated by refitting based on the most recent historical operating condition data of the set time period.

[0109] As you can understand, the heat pump power prediction model, updated based on the latest historical operating data, reflects the latest operating status of the heat pump and PV energy storage system. The expected heat pump operating power determined based on this model is more accurate and reflects the latest status of the overall system. The updated prediction model is more adaptable to changes in actual heat pump power due to age, blockage, aging, and / or weather changes, resulting in more accurate expected heat pump operating power. This ensures precise regulation of the outlet water temperature, maintains stable heat pump charging operation, and maximizes the utilization of available PV charging power.

[0110] The present application also provides an energy storage control method, wherein optional temperature increments include: -2, -1, +1, and +2; the initial outlet water set temperature T0 for heat pump heating is 45 degrees Celsius; the first ratio is 1.25, the second ratio is 0.83, and the third ratio is 0.20; the current available photovoltaic heating power P_hot = the current photovoltaic power generation power P_power - the other load power P_other; the expected heat pump operating power P_predict; the current heat pump operating power P_real; the rated heating power P_rated of the heat pump device; and the current outlet water set temperature T. The lower limit of the outlet water set temperature is 38 degrees Celsius and the upper limit is 75 degrees Celsius. The energy storage control method is shown in FIG5 and includes:

[0111] Step 500, the photovoltaic energy storage system is started (heat pump is started);

[0112] Step 510 , calculate the difference P_surplus_start=P_power−P_other−P_rated;

[0113] Step 520, determine whether P_surplus_start>20%*P_rated, if greater than, execute step 5100, if less than or equal to, wait for the next execution of 510;

[0114] Step 5100: Start the photovoltaic heating mode at the initial outlet water setting temperature T0. After the current outlet water setting temperature T=T0 is maintained for a certain period of time, execute step 5110.

[0115] Step 5110 , calculate the difference P_surplus=P_power-P_other-P_real;

[0116] Step 5120, determine whether P_surplus is positive or negative; if it is negative, execute step 5200; if it is positive, execute step 5300; if it is 0, execute step 5360;

[0117] Step 5200 , obtaining the expected heat pump operating power P_predict corresponding to the candidate outlet water set temperature T-1;

[0118] Step 5210: Determine whether P_power - P_other - 0.83 * P_predict > 0. If so, execute 5220; if less than or equal to 0, execute 5230.

[0119] Step 5220, determine the target outlet water set temperature as T-1 and adjust it;

[0120] Step 5230 , obtaining the expected heat pump operating power P_predict corresponding to the candidate outlet water set temperature T-2;

[0121] Step 5240: Determine whether P_power - P_other - 0.83 * P_predict > 0. If so, execute 5250; if less than or equal to 0, execute 5260.

[0122] Step 5250, determine the target outlet water set temperature as T-2 and adjust it;

[0123] Step 5260, exiting the photovoltaic heating mode;

[0124] Step 5300: Obtain the expected heat pump operating power P_predict corresponding to the candidate outlet water set temperature T+2;

[0125] Step 5310: Determine whether P_power - P_other - 1.25 * P_predict > 0. If so, execute 5320; if less than or equal to 0, execute 5330.

[0126] Step 5320, determine the target outlet water set temperature as T+2 and adjust it;

[0127] Step 5330 , obtaining the expected heat pump operating power P_predict corresponding to the candidate outlet water set temperature T+1;

[0128] Step 5340: Determine whether P_power - P_other - 1.25 * P_predict > 0. If so, execute 5350; if less than or equal to 0, execute 5360.

[0129] Step 5350: Determine the target outlet water set temperature as T+1 and adjust it;

[0130] Step 5360: Determine the target outlet water set temperature as T+0, i.e., the outlet water set temperature remains unchanged;

[0131] Step 5400, waiting for the next control cycle.

[0132] For example, a PV energy storage system includes a heat pump device with a maximum heating capacity of 12kW and a rated heating power P_rated of 2.5kW. The current outdoor temperature is 0°C. When P_surplus_start = P_power - P_other - P_rated, which is greater than 0.5kW, the system enters PV heating mode with an initial outlet water temperature set at 45°C. Two minutes later, if the PV power increases or other load power decreases, causing the current available PV heating power P_hot = P_power - P_other to increase, then assuming the candidate outlet water temperature set point is 47°C, the current available PV heating power P_hot is calculated as P_power - P_other - 1.25 * P_predict. If the current available PV heating power P_hot is greater than 0, the outlet water temperature set point of 47°C is issued.

[0133] The embodiment of the present application further provides a photovoltaic heat pump system, as shown in FIG6 , comprising:

[0134] A control device 610, a photovoltaic device 620 and a heat pump device 630 electrically connected to the control device 610, and a hot water storage tank 640 in communication with the heat pump device 630;

[0135] The control device 610 is configured to execute the energy storage control method as described in any embodiment of the present application.

[0136] It is understood that in some exemplary embodiments, the control device 610 executes a method to control the photovoltaic heat pump system to enter the photovoltaic heating mode. In some exemplary embodiments, the control device 610 executes a method to control the photovoltaic heat pump system to periodically adjust the outlet water set temperature to adjust the heat pump operating power based on the difference between the current available photovoltaic heating power and the current heat pump operating power after entering the photovoltaic heating mode, so that the heat pump operating power can change in a positive correlation with the available photovoltaic heating power.

[0137] In some exemplary embodiments, the system also includes: an operating condition data fitting module 650, which is configured to obtain a heat pump power prediction model based on the historical operating condition data of the heat pump equipment, so as to obtain the operating power of the heat pump equipment based on the outlet water set temperature and the outdoor ambient temperature of the heat pump equipment.

[0138] In some exemplary embodiments, the operating condition data fitting module 650 is further configured to collect and save the operating condition data according to a set collection rule.

[0139] In some exemplary embodiments, the operating condition data fitting module 650 is further configured to update the heat pump power prediction model by refitting the historical operating condition data of the most recent set duration according to a set model update time schedule.

[0140] An embodiment of the present application further provides an electronic device, including:

[0141] one or more processors;

[0142] a storage device for storing one or more programs,

[0143] When the one or more programs are executed by the one or more processors, the one or more processors implement the energy storage control method as described in any embodiment of the present application.

[0144] An embodiment of the present application further provides a computer storage medium, wherein the storage medium stores a computer program, wherein the computer program is configured to execute the energy storage control method as described in any embodiment of the present application when running.

[0145] The energy storage control solution provided in the embodiment of the present application adjusts the operating power of the heat pump in the heating mode by adjusting the outlet water set temperature, so that the real-time operating power of the heat pump changes with the photovoltaic power generation power, ensuring that the photovoltaic power generation can continue to supply power to the heat pump when the photovoltaic power generation power fluctuates within a certain range, maintaining the operating stability of the overall system, and maximizing the utilization of the available photovoltaic heating power, thereby improving the overall system efficiency.

[0146] It will be appreciated by those skilled in the art that all or some of the steps, systems, and functional modules / units in the methods disclosed above may be implemented as software, firmware, hardware, and appropriate combinations thereof. In hardware implementations, the division between the functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed by several physical components in cooperation. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or non-transitory medium) and a communication medium (or temporary medium). As is well known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable, and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. In addition, it is well known to those skilled in the art that communication media generally embodies computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

Claims

1. A method for controlling energy storage, wherein: Applied to a photovoltaic heat pump system, the photovoltaic heat pump system includes a photovoltaic device, a heat pump device, and a hot water storage tank connected to the heat pump device. The energy storage control method includes: In the photovoltaic thermal charging mode, the following processes are performed periodically: According to the difference between the current available photovoltaic heating power and the current heat pump operating power, the outlet water set temperature is adjusted to adjust the heat pump operating power, so that the heat pump operating power can change in a positively correlated manner with the change in the available photovoltaic heating power; The available photovoltaic heating power is the power of the photovoltaic power generation that can be used to supply power to the heat pump to heat the hot water storage tank.

2. The energy storage control method according to claim 1, wherein: The step of adjusting the outlet water set temperature to adjust the heat pump operating power according to the difference between the current available photovoltaic heating power and the current heat pump operating power includes: selecting an available temperature increment, and if selected, determining a target outlet water set temperature based on the selected temperature increment; and adjusting the current outlet water set temperature to the determined target outlet water set temperature; The step of determining the target outlet water setting temperature based on the selected temperature increment includes: performing the following judgment on the selected temperature increment: adding the temperature increment to the current outlet water setting temperature to obtain a candidate outlet water setting temperature, and determining the expected heat pump operating power at the candidate outlet water setting temperature; judging whether the currently available photovoltaic heating power and the expected heat pump operating power meet a preset adjustment condition, and if so, determining the candidate outlet water setting temperature as the target outlet water setting temperature; The available temperature increment has the same sign as the difference, and the candidate outlet water setting temperature obtained by adding the available temperature increment to the current outlet water setting temperature is within an allowable outlet water setting temperature range.

3. The energy storage control method according to claim 2, wherein: When the difference is positive and multiple temperature increments are selected, the judgment is performed one by one on the multiple selected temperature increments in descending order until the target outlet water setting temperature is determined. If the judgment has been performed on all the multiple selected temperature increments but the target outlet water setting temperature has not yet been determined, the current outlet water setting temperature is determined as the target outlet water setting temperature.

4. The energy storage control method according to claim 2, wherein: When the difference is negative and multiple temperature increments are selected, the judgment is performed one by one on the multiple selected temperature increments in descending order until the target water outlet set temperature is determined. If the judgment has been performed on all the multiple selected temperature increments but the target water outlet set temperature has not been determined, the photovoltaic thermal charging mode is exited.

5. The energy storage control method according to claim 2, wherein: The determining whether the currently available photovoltaic heating power and the expected heat pump operating power meet a preset adjustment condition includes: When the available temperature increment is positive, determining whether the currently available photovoltaic charging power is greater than a first ratio of the expected heat pump operating power, the first ratio being greater than 1; When the available temperature increment is negative, it is determined whether the currently available photovoltaic thermal charging power is greater than a second ratio of the expected heat pump operating power, the second ratio being less than 1.

6. The energy storage control method according to any one of claims 2 to 5, wherein: The step of adjusting the outlet water set temperature to adjust the heat pump operating power based on the difference between the current available photovoltaic heating power and the current heat pump operating power may also include any one or more of the following: When the current outlet water set temperature is the upper limit temperature and the sign of the difference is positive, the current outlet water set temperature is maintained unchanged or the photovoltaic heating mode is exited; When the current outlet water set temperature is the lower limit temperature and the difference sign is negative, when the ratio of the current available photovoltaic heating power to the current heat pump operating power is greater than or equal to the preset minimum ratio, the current outlet water set temperature is maintained unchanged; when the ratio of the current available photovoltaic heating power to the current heat pump operating power is less than the preset minimum ratio, the photovoltaic heating mode is exited; The current temperature of the hot water storage tank is obtained, and when the current temperature of the hot water storage tank reaches the upper limit temperature of the hot water storage tank and the sign of the difference is positive, the photovoltaic thermal charging mode is exited.

7. The energy storage control method according to any one of claims 1 to 5, wherein: The method further comprises: When it is determined that the heat pump charging condition is met based on the difference between the currently available photovoltaic heating power and the rated heating power of the heat pump device, the photovoltaic heat pump system starts to operate in the photovoltaic heating mode.

8. The energy storage control method according to claim 2, wherein: The expected heat pump operating power at the candidate outlet water set temperature is determined according to one of the following methods: Determining the heat pump operating power using a heat pump power prediction model based on the candidate outlet water temperature and the current outdoor ambient temperature; The heat pump operating power is determined by looking up a preset heat pump operating power lookup table according to the candidate outlet water temperature and the current outdoor ambient temperature.

9. The energy storage control method according to claim 8, wherein: The heat pump power prediction model is obtained by fitting the historical operating data of the heat pump equipment; The historical operating condition data includes multiple sets of data collected within the most recent set period of time, and each set of data includes the outlet water set temperature, the outdoor ambient temperature and the heat pump operating power.

10. The energy storage control method according to claim 8 or 9, wherein: The heat pump power prediction model is the following function: Among them, P is the heat pump operating power, TempSetting is the target water outlet temperature, T E is the outdoor ambient temperature, K1, K2, K3, b2, b3 are model parameters, and T1 is the preset temperature value.

11. A photovoltaic heat pump system, wherein: include: a control device, a photovoltaic device and a heat pump device electrically connected to the control device, and a hot water storage tank in communication with the heat pump device; Wherein, the control device is configured to execute the energy storage control method according to any one of claims 1-10.

12. The photovoltaic heat pump system according to claim 11, wherein: Also includes: The operating condition data fitting module is configured to obtain a heat pump power prediction model based on the historical operating condition data of the heat pump device, so as to obtain the operating power of the heat pump device based on the outlet water set temperature of the heat pump device and the outdoor ambient temperature.

13. An electronic device, wherein: include: one or more processors; a storage device for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors implement the energy storage control method according to any one of claims 1 to 10.

14. A computer storage medium, wherein: The storage medium stores a computer program, wherein the computer program is configured to execute the energy storage control method according to any one of claims 1 to 10 when running.

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