Photovoltaic energy storage equipment, control method and control device thereof and readable storage medium

Abstract

The invention provides photovoltaic energy storage equipment, a control method and device thereof and a readable storage medium, and relates to the technical field of photovoltaic control. The control method comprises the following steps: acquiring a feed network power value of a feed network electric signal; determining a feed network power reference value according to the feed network power value and the feed network power limit value; determining a target power limit value based on a comparison result of the feed network power reference value and a preset reference value interval; wherein the target power limit value comprises at least one of the following items: the maximum value of the generated power of the photovoltaic power generation assembly, the maximum value of the discharge power of the energy storage assembly and the maximum value of the output power of the inverter output end; and controlling the photovoltaic energy storage equipment to output a feed network electric signal based on the target power limit value. According to the invention, stable and reliable adjustment of the power of the feed network can be realized, so that the power of the feed network of the photovoltaic energy storage equipment is limited to a proper range, and the stable requirement of the feed network is met.

Description

Technical Field

[0001] This application relates to the field of photovoltaic control technology, and more particularly, to a photovoltaic energy storage device and its control method, control apparatus and readable storage medium. Background Technology

[0002] In related technologies, photovoltaic energy storage equipment includes a photovoltaic (PV) power generation component, a converter, and a load component. The load component can be a battery or electrical equipment, or it can be the power grid, i.e., feeding power to the grid. However, due to the stability requirements of the grid side, sudden changes in the power fed to the grid may lead to grid fluctuations. Therefore, ensuring the stable and reliable power fed to the grid is an urgent problem to be solved. Summary of the Invention

[0003] This application aims to address at least one of the technical problems existing in the prior art or related technologies.

[0004] Therefore, the first aspect of this application proposes a control method for a photovoltaic energy storage device.

[0005] The second aspect of this application proposes a control device for a photovoltaic energy storage device.

[0006] The third aspect of this application proposes a control device for a photovoltaic energy storage device.

[0007] The fourth aspect of this application proposes a readable storage medium.

[0008] The fifth aspect of this application proposes a photovoltaic energy storage device.

[0009] In view of the above, the first aspect of this application provides a control method for a photovoltaic energy storage device. The photovoltaic energy storage device includes a photovoltaic power generation module, an energy storage module, and an energy storage converter. The energy storage converter includes an inverter output terminal for outputting a grid-feed power signal. The control method includes: acquiring the grid-feed power value of the grid-feed power signal; determining a grid-feed power reference value based on the grid-feed power value and a grid-feed power limit; determining a target power limit based on a comparison result between the grid-feed power reference value and a preset reference value range; wherein the target power limit includes at least one of the following: the maximum power generation of the photovoltaic power generation module, the maximum discharge power of the energy storage module, and the maximum output power of the inverter output terminal; and controlling the photovoltaic energy storage device to output the grid-feed power signal based on the target power limit.

[0010] In this technical solution, the photovoltaic energy storage device includes a photovoltaic (PV) power generation module, a power conversion system (PCS), and an energy storage module. The DC terminal of the energy storage converter is electrically connected to the photovoltaic power generation module and the energy storage module, and the AC terminal of the energy storage converter can be connected to the load and the power grid. Here, the inverter output terminal of the energy storage converter is defined to output a grid feed signal to the power grid.

[0011] The purpose of this application is to ensure the stability of the power of the aforementioned feeder signal. To this end, this application acquires the feeder power value of the feeder signal output by the energy storage converter in real time and obtains the feeder power limit. For example, the feeder power limit issued by the grid-side meter can be obtained through the communication connection between the energy storage converter and the grid-side meter. For example, the feeder power limit can also be manually set by the user.

[0012] After obtaining the actual grid power value and the set grid power limit, the two are compared through the power loop, and the comparison result is determined. The comparison result reflects whether the power fed to the grid by the inverter output of the energy storage converter matches the set grid power limit. Based on the comparison result, the target power limit is determined. The target power limit is used to limit one or more of the power generation of the photovoltaic power generation module, the discharge power of the energy storage module, and the output power of the inverter output.

[0013] For example, photovoltaic energy storage devices can invert the electrical energy generated by photovoltaic power generation modules through an energy storage converter and output it to the grid. Therefore, the power generation of the photovoltaic power generation modules will affect the grid feed power. Simultaneously, in some scenarios, such as when the energy storage module is fully charged and the load demand is very low, the electrical energy stored in the energy storage module can also be inverted through the energy storage converter and output to the grid. In this case, the discharge power of the energy storage module will also affect the grid feed power. Therefore, the grid feed power can be regulated by adjusting the power generation of the photovoltaic power generation modules and the discharge power of the energy storage module.

[0014] In some cases, if the grid power still cannot meet the grid power limit after adjusting the power generation of photovoltaic power generation modules and the discharge power of energy storage modules, it is necessary to further adjust the output power of the inverter output terminal of the energy storage converter to fundamentally ensure that the output power of the inverter output terminal meets the grid power limit.

[0015] The technical solution of this application can achieve stable and reliable regulation of the grid feed power, thereby limiting the grid feed power of the photovoltaic energy storage equipment to a suitable range and meeting the grid stability requirements.

[0016] In addition, the control method for the photovoltaic energy storage device in the above-mentioned technical solution provided in this application may also have the following additional technical features:

[0017] In some technical solutions of this application, optionally, a feeder power reference value is determined based on the feeder power value and the feeder power limit, including: performing proportional-integral control processing and slope compensation processing on the difference between the feeder power limit and the feeder power value to obtain the feeder power reference value.

[0018] In this technical solution, the difference between the grid power limit and the actual obtained grid power value can reflect whether the grid power of the photovoltaic energy storage device meets the demand. By determining the difference between the two through the power loop, power closed-loop control can be performed, which can enable the actual grid power to track the grid power limit, thereby improving grid efficiency while ensuring that the grid power is stable and does not exceed the limit.

[0019] After obtaining the power loop output, the output value is further processed by proportional-integral (PI) control and then by slope compensation to obtain the aforementioned feeder power reference value. This application uses power loop control based on the set feeder power limit and the actual collected feeder power value to enable the photovoltaic energy storage device to maximize feeder efficiency without exceeding the limits.

[0020] In some embodiments of this application, optionally, the range of the grid power reference value is [-3, 0]; determining the target power limit based on the comparison result between the grid power reference value and the preset reference value range includes: determining the maximum power output of the photovoltaic power generation module according to the grid power reference value when the grid power reference value meets the first preset reference value range; controlling the output of the grid power signal of the photovoltaic energy storage device based on the target power limit includes: controlling the operation of the photovoltaic power generation module based on the maximum power output and controlling the output of the grid power signal of the energy storage converter; wherein, the first preset reference value range is [-1, 0].

[0021] In the technical solution of this application, the difference between the feed grid power limit and the actual obtained feed grid power value is processed by power loop and proportional integral, and then by slope compensation to limit the obtained value to the range of [-3, 0], thus obtaining the above-mentioned feed grid power reference value.

[0022] In actual control, the range [-3, 0] of the above-mentioned grid power reference value is segmented. When adjusting the grid power, limiting the output power of the photovoltaic power generation modules is preferred, which can reduce the impact on the control logic of the energy storage modules and the control logic of the energy storage converter.

[0023] For example, if the grid power reference value meets the first preset reference range [-1, 0], then only the power generation of the photovoltaic power generation module is adjusted, and the grid power value is limited by limiting the maximum power generation of the photovoltaic power generation module.

[0024] Specifically, when the output of the PI circuit is in the range of [-1, 0], the power output limit of the PV module is in the range of [0, 1], which can limit the power of the PV module. When the maximum power output is 0, it means that the power output of the PV module is 0, that is, the PV module does not output power. When the maximum power output is 1, it means that the power output of the PV module is not limited.

[0025] When the output power limit of the PV is within the range of [0, 1], the maximum discharge power of the energy storage module is within the range of [1, 2]. After limiting, the maximum discharge power of the energy storage module is 1, and therefore it is unrestricted. Similarly, the maximum output power of the inverter end of the energy storage converter is within the range of [2, 3]. After limiting, its value is also 1, so the inverter side is also unrestricted. In this case, limiting only the output power of the PV is sufficient to achieve the goal.

[0026] When the power of the feeder exceeds the limit, the technical solution of this application prioritizes adjusting the output power limit on the PV side, which can limit the power of the feeder to a reasonable range and has a small impact on the system.

[0027] In some embodiments of this application, optionally, the range of the grid power reference value is [-3, 0]; determining the target power limit based on the comparison result between the grid power reference value and the preset reference value range includes: when the grid power reference value meets the second preset reference value range, determining the maximum power output of the photovoltaic power generation module and the maximum discharge power of the energy storage module according to the grid power reference value; controlling the output of the grid power signal of the photovoltaic energy storage device based on the target power limit includes: controlling the operation of the photovoltaic power generation module based on the maximum power output, controlling the discharge of the energy storage module based on the maximum discharge power, and controlling the output of the grid power signal of the energy storage converter; wherein, the second preset reference value range is [-2, -1].

[0028] In the technical solution of this application, the difference between the feed grid power limit and the actual obtained feed grid power value is processed by power loop and proportional integral, and then by slope compensation to limit the obtained value to the range of [-3, 0], thus obtaining the above-mentioned feed grid power reference value.

[0029] In actual control, the range [-3, 0] of the aforementioned grid power reference value is segmented. When adjusting the grid power, limiting the output power of the photovoltaic (PV) modules is preferred to reduce the impact on the control logic of the energy storage modules and the energy storage converter. However, if limiting the output power of the PV modules still fails to meet the grid power limit requirements, or if the voltage of the PV modules exceeds the controllable range, causing the control loop of the PV modules to fail, then further adjustment of the discharge power of the energy storage modules is required.

[0030] For example, if the grid power reference value meets the second preset reference range [-2, -1], then adjusting the power generation of the photovoltaic power generation module alone cannot meet the grid power limit, and it is necessary to further limit the discharge power of the energy storage module.

[0031] When the output of the PI circuit is in the range of [-2, -1], the value of the PV circuit is in the range of [-1, 0]. After limiting, it becomes 0, meaning the power of the PV circuit is limited to 0, and the PV output is turned off. The maximum discharge power of the energy storage module is in the range of [0, 1], thus partially limiting the discharge power of the energy storage module. The maximum output power of the inverter end of the energy storage converter is in the range of [1, 2]. After limiting, its value is 1, therefore the inverter side is unrestricted. In this case, it is necessary to simultaneously limit the output power of the PV circuit and the discharge power of the energy storage module to achieve the desired result.

[0032] When the grid power exceeds the limit, the technical solution of this application prioritizes adjusting the output power limit of the PV side. If adjusting only the output power limit of the PV side cannot meet the requirements, the discharge power of the battery module is further adjusted to ensure that the grid power is limited to a reasonable range.

[0033] In some embodiments of this application, optionally, the range of the grid power reference value is [-3, 0]; determining the target power limit based on the comparison result between the grid power reference value and the preset reference value range includes: when the grid power reference value meets the third preset reference value range, determining the maximum power generation of the photovoltaic power generation module, the maximum discharge power of the energy storage module, and the maximum output power of the inverter output terminal according to the grid power reference value; controlling the output of the grid power signal of the photovoltaic energy storage device based on the target power limit includes: controlling the operation of the photovoltaic power generation module based on the maximum power generation, controlling the discharge of the energy storage module based on the maximum discharge power, and controlling the output of the grid power signal of the energy storage converter based on the maximum output power of the inverter output terminal; wherein, the third preset reference value range is [-3, -2].

[0034] In this technical solution, the difference between the feeder power limit and the actual feeder power value is processed by power loop and proportional-integral method, and then by slope compensation, so that the obtained value is limited to the range of [-3, 0], thus obtaining the above-mentioned feeder power reference value.

[0035] In actual control, the range [-3, 0] of the aforementioned grid power reference value is segmented. When adjusting the grid power, limiting the output power of the photovoltaic power generation modules is preferred, as it reduces the impact on the control logic of the energy storage modules and the energy storage converter. However, if limiting the output power of the photovoltaic power generation modules and the discharge power of the energy storage modules still cannot meet the grid power limit requirements, then to ensure that the grid power does not exceed the limit, the output power of the inverter side port of the energy storage converter is limited, thereby fundamentally solving the problem of grid power exceeding the limit.

[0036] For example, if the grid power reference value meets the third preset reference range [-3, -2], then adjusting the power generation of the photovoltaic power generation module alone cannot meet the grid power limit, and it is necessary to further limit the discharge power of the energy storage module.

[0037] In this scenario, when the PI circuit output is in the range of [-3, -2], the PV output is in the range of [-2, -1], which, after limiting, becomes 0, meaning the PV power is limited to 0, and the PV output is shut down. Similarly, the maximum discharge power of the energy storage module is in the range of [-1, 0], which, after limiting, becomes 0, meaning the energy storage module's discharge power is limited to 0, and the energy storage module stops discharging. The maximum output power of the inverter terminal of the energy storage converter is in the range of [0, 1], thus limiting the inverter port. In this case, the maximum power output of the photovoltaic module, the maximum discharge power of the energy storage module, and the maximum output power of the inverter terminal all need to be limited to achieve the desired result.

[0038] Understandably, when the output of the PI circuit is within the range of [-2, 0], limiting the output power of the PV module and the discharge power of the energy storage module can satisfy the limitation on the grid power. According to the law of conservation of energy, the power generation of the PV module, the discharge power of the energy storage module, and the output power of the inverter satisfy the following constraints:

[0039] Pcs_Power=Pv_Power+Bat_Power.

[0040] Where Pcs_Power is the output power of the inverter output terminal of the energy storage converter, Pv_Power is the power generation power of the photovoltaic power generation module, and Bat_Power is the discharge power of the energy storage module.

[0041] When the voltage of the photovoltaic (PV) power generation module is within a controllable range, if the voltage is too high, the control loop of the PV power generation module will fail, and the power limit value of the PV power generation module will be invalid. The same applies to the energy storage module. However, even if the control of both the PV power generation module and the energy storage module fails, this application can still fundamentally solve the problem of grid power exceeding the limit by limiting the maximum output power of the inverter output terminal of the energy storage converter, ensuring that the final grid power is limited to below the set grid power limit.

[0042] In some technical solutions of this application, the target power limit is determined based on the comparison results between the feed grid power reference value and the preset reference value range, including: determining the target offset value based on the comparison results; and performing slope compensation processing on the sum of the feed grid power reference value and the target offset value to obtain the target power limit.

[0043] In this technical solution, after obtaining the actual feed grid power value and the set feed grid power limit, the two are compared through a power loop, and a target offset value is determined based on the comparison result. This target offset value is used to instruct the control loop to adjust the feed grid power. To ensure that the control value can be executed without error, this application adds a proportional-integral (PI) control loop after the power loop. After the target offset value is processed by PI control, it is then processed by slope compensation to obtain the aforementioned target power limit. The slope compensation process ensures that the target power limit is within the range of [0, 1].

[0044] The technical solution of this application can achieve stable and reliable regulation of the grid feed power, thereby limiting the grid feed power of the photovoltaic energy storage equipment to a suitable range and meeting the grid stability requirements.

[0045] The second aspect of this application provides a control device for a photovoltaic energy storage device. The photovoltaic energy storage device includes a photovoltaic power generation module, an energy storage module, and an energy storage converter. The energy storage converter includes an inverter output terminal for outputting a grid-feed power signal. The control device includes: an acquisition module for acquiring the grid-feed power value of the grid-feed power signal; a determination module for determining a grid-feed power reference value based on the grid-feed power value and a grid-feed power limit; and a target power limit for determining a target power limit based on a comparison between the grid-feed power reference value and a preset reference value range. The target power limit includes at least one of the following: the maximum power output of the photovoltaic power generation module, the maximum discharge power of the energy storage module, and the maximum output power of the inverter output terminal. The control module is used to control the output of the grid-feed power signal by the photovoltaic energy storage device based on the target power limit.

[0046] In this technical solution, the photovoltaic energy storage device includes a photovoltaic (PV) power generation module, a power conversion system (PCS), and an energy storage module. The DC terminal of the energy storage converter is electrically connected to the photovoltaic power generation module and the energy storage module, and the AC terminal of the energy storage converter can be connected to the load and the power grid. Here, the inverter output terminal of the energy storage converter is defined to output a grid feed signal to the power grid.

[0047] The purpose of this application is to ensure the stability of the power of the aforementioned feeder signal. To this end, this application acquires the feeder power value of the feeder signal output by the energy storage converter in real time and obtains the feeder power limit. For example, the feeder power limit issued by the grid-side meter can be obtained through the communication connection between the energy storage converter and the grid-side meter. For example, the feeder power limit can also be manually set by the user.

[0048] After obtaining the actual grid power value and the set grid power limit, the two are compared through the power loop, and the comparison result is determined. The comparison result reflects whether the power fed to the grid by the inverter output of the energy storage converter matches the set grid power limit. Based on the comparison result, the target power limit is determined. The target power limit is used to limit one or more of the power generation of the photovoltaic power generation module, the discharge power of the energy storage module, and the output power of the inverter output.

[0049] For example, photovoltaic energy storage devices can invert the electrical energy generated by photovoltaic power generation modules through an energy storage converter and output it to the grid. Therefore, the power generation of the photovoltaic power generation modules will affect the grid feed power. Simultaneously, in some scenarios, such as when the energy storage module is fully charged and the load demand is very low, the electrical energy stored in the energy storage module can also be inverted through the energy storage converter and output to the grid. In this case, the discharge power of the energy storage module will also affect the grid feed power. Therefore, the grid feed power can be regulated by adjusting the power generation of the photovoltaic power generation modules and the discharge power of the energy storage module.

[0050] In some cases, if the grid power still cannot meet the grid power limit after adjusting the power generation of photovoltaic power generation modules and the discharge power of energy storage modules, it is necessary to further adjust the output power of the inverter output terminal of the energy storage converter to fundamentally ensure that the output power of the inverter output terminal meets the grid power limit.

[0051] A third aspect of this application provides a control device for a photovoltaic energy storage device, comprising: a memory for storing programs or instructions; and a processor for executing programs or instructions to implement the steps of the control method for the photovoltaic energy storage device provided in any of the above technical solutions. Therefore, it also includes all the beneficial effects of the control method for the photovoltaic energy storage device provided in any of the above technical solutions, and will not be repeated here to avoid repetition.

[0052] The fourth aspect of this application provides a readable storage medium having a program or instructions stored thereon. When the program or instructions are executed by a processor, they implement the steps of the control method for the photovoltaic energy storage device provided in any of the above technical solutions. Therefore, it also includes all the beneficial effects of the control method for the photovoltaic energy storage device provided in any of the above technical solutions. To avoid repetition, these will not be repeated here.

[0053] The fifth aspect of this application provides a photovoltaic energy storage device, including a control device for the photovoltaic energy storage device as provided in any of the above-described technical solutions; and / or a readable storage medium as provided in any of the above-described technical solutions. Therefore, it also includes all the beneficial effects of the control device for the photovoltaic energy storage device as provided in any of the above-described technical solutions; and / or the readable storage medium as provided in any of the above-described technical solutions, which will not be repeated here to avoid repetition. Attached Figure Description

[0054] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0055] Figure 1 A flowchart illustrating a control method for a photovoltaic energy storage device according to some embodiments of this application is shown;

[0056] Figure 2 The following are control schematic diagrams of photovoltaic energy storage devices according to some embodiments of this application;

[0057] Figure 3 The present application shows a structural block diagram of the control device of a photovoltaic energy storage device according to some embodiments;

[0058] Figure 4 A structural block diagram of the control device for a photovoltaic energy storage device according to some embodiments of this application is shown. Detailed Implementation

[0059] To better understand the above-mentioned objectives, features, and advantages of this application, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0060] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.

[0061] The following reference Figures 1 to 4 This application describes a photovoltaic energy storage device and its control method, control apparatus, and readable storage medium provided according to some embodiments.

[0062] The markings in the following figures are explained as follows:

[0063] Power_Lmt is the power limit value for the feeder network, which is set by the customer;

[0064] Grid_Power_fdb is the feedback value of the feeder power;

[0065] Pv_Power_max is the maximum value of the PV output power;

[0066] Bat_DisCharge_Power_max is the maximum value of battery discharge;

[0067] Pcs_Power_max is the maximum power of the inverter-side feed grid.

[0068] In some embodiments of this application, a control method for a photovoltaic energy storage device is provided. The photovoltaic energy storage device includes a photovoltaic power generation module, an energy storage module, and an energy storage converter. The energy storage converter includes an inverter output terminal, which is used to output a grid-feed power signal.

[0069] Figure 1 A flowchart illustrating a control method for a photovoltaic energy storage device according to some embodiments of this application is shown, such as... Figure 1 As shown, the control methods include:

[0070] Step 102: Obtain the feeder power value of the feeder signal;

[0071] Step 104: Determine the feeder power reference value based on the feeder power value and the feeder power limit;

[0072] Step 106: Based on the comparison results between the grid power reference value and the preset reference value range, determine the target power limit; wherein, the target power limit includes at least one of the following: the maximum power generation of the photovoltaic power generation module, the maximum discharge power of the energy storage module, and the maximum output power of the inverter output terminal;

[0073] Step 108: Control the output grid power signal of the photovoltaic energy storage device based on the target power limit.

[0074] In this embodiment, the photovoltaic energy storage device includes a photovoltaic (PV) power generation module, a power conversion system (PCS), and an energy storage module. The DC terminal of the power conversion system is electrically connected to the photovoltaic power generation module and the energy storage module, and the AC terminal of the power conversion system can be connected to the load and the power grid. Here, the inverter output terminal of the power conversion system is defined to output a grid feed signal to the power grid.

[0075] The purpose of this application is to ensure the stability of the power of the aforementioned feeder signal. To this end, this application acquires the feeder power value of the feeder signal output by the energy storage converter in real time and obtains the feeder power limit. For example, the feeder power limit issued by the grid-side meter can be obtained through the communication connection between the energy storage converter and the grid-side meter. For example, the feeder power limit can also be manually set by the user.

[0076] Figure 2 The following are control schematic diagrams of photovoltaic energy storage devices according to some embodiments of this application, such as... Figure 2 As shown, after obtaining the actual grid power value and the set grid power limit, the two are compared through the power loop, and the comparison result is determined. The comparison result reflects whether the power fed to the grid by the inverter output of the energy storage converter matches the set grid power limit. Based on the comparison result, the target power limit is determined. Through the target power limit, one or more of the power generation of the photovoltaic power generation module, the discharge power of the energy storage module, and the output power of the inverter output are limited.

[0077] For example, photovoltaic energy storage devices can invert the electrical energy generated by photovoltaic power generation modules through an energy storage converter and output it to the grid. Therefore, the power generation of the photovoltaic power generation modules will affect the grid feed power. Simultaneously, in some scenarios, such as when the energy storage module is fully charged and the load demand is very low, the electrical energy stored in the energy storage module can also be inverted through the energy storage converter and output to the grid. In this case, the discharge power of the energy storage module will also affect the grid feed power. Therefore, the grid feed power can be regulated by adjusting the power generation of the photovoltaic power generation modules and the discharge power of the energy storage module.

[0078] In some cases, if the grid power still cannot meet the grid power limit after adjusting the power generation of photovoltaic power generation modules and the discharge power of energy storage modules, it is necessary to further adjust the output power of the inverter output terminal of the energy storage converter to fundamentally ensure that the output power of the inverter output terminal meets the grid power limit.

[0079] The embodiments of this application can achieve stable and reliable adjustment of the grid power, thereby limiting the grid power of the photovoltaic energy storage equipment to a suitable range and meeting the grid stability requirements.

[0080] In some embodiments of this application, optionally, determining a feeder power reference value based on the feeder power value and the feeder power limit includes: performing proportional-integral control processing and slope compensation processing on the difference between the feeder power limit and the feeder power value to obtain the feeder power reference value.

[0081] In this embodiment, the difference between the grid power limit and the actual obtained grid power value can reflect whether the grid power of the photovoltaic energy storage device meets the requirements. By determining the difference between the two through the power loop, power closed-loop control can be performed, which can enable the actual grid power to track the grid power limit, thereby improving grid efficiency while ensuring that the grid power is stable and does not exceed the limit.

[0082] After obtaining the power loop output, the output value is further processed by proportional-integral (PI) control and then by slope compensation to obtain the aforementioned feeder power reference value. This application uses power loop control based on the set feeder power limit and the actual collected feeder power value to enable the photovoltaic energy storage device to maximize feeder efficiency without exceeding the limits.

[0083] In some embodiments of this application, optionally, the range of the grid power reference value is [-3, 0]; determining the target power limit based on the comparison result between the grid power reference value and the preset reference value range includes: determining the maximum power output of the photovoltaic power generation module according to the grid power reference value when the grid power reference value meets the first preset reference value range; controlling the output of the grid power signal of the photovoltaic energy storage device based on the target power limit includes: controlling the operation of the photovoltaic power generation module based on the maximum power output and controlling the output of the grid power signal of the energy storage converter; wherein, the first preset reference value range is [-1, 0].

[0084] In this embodiment of the application, the difference between the feed power limit and the actual obtained feed power value is processed by power loop and proportional integral, and then by slope compensation to limit the obtained value to the range of [-3, 0], thus obtaining the above-mentioned feed power reference value.

[0085] In actual control, the range [-3, 0] of the above-mentioned grid power reference value is segmented. When adjusting the grid power, limiting the output power of the photovoltaic power generation modules is preferred, which can reduce the impact on the control logic of the energy storage modules and the control logic of the energy storage converter.

[0086] For example, if the grid power reference value meets the first preset reference range [-1, 0], then only the power generation of the photovoltaic power generation module is adjusted, and the grid power value is limited by limiting the maximum power generation of the photovoltaic power generation module.

[0087] Specifically, when the output of the PI circuit is in the range of [-1, 0], the power output limit of the PV module is in the range of [0, 1], which can limit the power of the PV module. When the maximum power output is 0, it means that the power output of the PV module is 0, that is, the PV module does not output power. When the maximum power output is 1, it means that the power output of the PV module is not limited.

[0088] When the output power limit of the PV is within the range of [0, 1], the maximum discharge power of the energy storage module is within the range of [1, 2]. After limiting, the maximum discharge power of the energy storage module is 1, and therefore it is unrestricted. Similarly, the maximum output power of the inverter end of the energy storage converter is within the range of [2, 3]. After limiting, its value is also 1, so the inverter side is also unrestricted. In this case, limiting only the output power of the PV is sufficient to achieve the goal.

[0089] In this embodiment of the application, when the power of the feed grid exceeds the limit, the output power limit on the PV side is adjusted first, so that the power of the feed grid can be limited to a reasonable range, and the impact on the system is small.

[0090] In some embodiments of this application, optionally, the range of the grid power reference value is [-3, 0]; determining the target power limit based on the comparison result between the grid power reference value and the preset reference value range includes: when the grid power reference value meets the second preset reference value range, determining the maximum power output of the photovoltaic power generation module and the maximum discharge power of the energy storage module according to the grid power reference value; controlling the output of the grid power signal of the photovoltaic energy storage device based on the target power limit includes: controlling the operation of the photovoltaic power generation module based on the maximum power output, controlling the discharge of the energy storage module based on the maximum discharge power, and controlling the output of the grid power signal of the energy storage converter; wherein, the second preset reference value range is [-2, -1].

[0091] In this embodiment of the application, the difference between the feed power limit and the actual obtained feed power value is processed by power loop and proportional integral, and then by slope compensation to limit the obtained value to the range of [-3, 0], thus obtaining the above-mentioned feed power reference value.

[0092] In actual control, the range [-3, 0] of the aforementioned grid power reference value is segmented. When adjusting the grid power, limiting the output power of the photovoltaic (PV) modules is preferred to reduce the impact on the control logic of the energy storage modules and the energy storage converter. However, if limiting the output power of the PV modules still fails to meet the grid power limit requirements, or if the voltage of the PV modules exceeds the controllable range, causing the control loop of the PV modules to fail, then further adjustment of the discharge power of the energy storage modules is required.

[0093] For example, if the grid power reference value meets the second preset reference range [-2, -1], then adjusting the power generation of the photovoltaic power generation module alone cannot meet the grid power limit, and it is necessary to further limit the discharge power of the energy storage module.

[0094] When the output of the PI circuit is in the range of [-2, -1], the value of the PV circuit is in the range of [-1, 0]. After limiting, it becomes 0, meaning the power of the PV circuit is limited to 0, and the PV output is turned off. The maximum discharge power of the energy storage module is in the range of [0, 1], thus partially limiting the discharge power of the energy storage module. The maximum output power of the inverter end of the energy storage converter is in the range of [1, 2]. After limiting, its value is 1, therefore the inverter side is unrestricted. In this case, it is necessary to simultaneously limit the output power of the PV circuit and the discharge power of the energy storage module to achieve the desired result.

[0095] In this embodiment of the application, when the power of the grid feed exceeds the limit, the output power limit of the PV side is adjusted first. If adjusting only the output power limit of the PV side cannot meet the requirements, the discharge power of the battery module is further adjusted to ensure that the power of the grid feed is limited to a reasonable range.

[0096] In some embodiments of this application, optionally, the range of the grid power reference value is [-3, 0]; determining the target power limit based on the comparison result between the grid power reference value and the preset reference value range includes: when the grid power reference value meets the third preset reference value range, determining the maximum power generation of the photovoltaic power generation module, the maximum discharge power of the energy storage module, and the maximum output power of the inverter output terminal according to the grid power reference value; controlling the output of the grid power signal of the photovoltaic energy storage device based on the target power limit includes: controlling the operation of the photovoltaic power generation module based on the maximum power generation, controlling the discharge of the energy storage module based on the maximum discharge power, and controlling the output of the grid power signal of the energy storage converter based on the maximum output power of the inverter output terminal; wherein, the third preset reference value range is [-3, -2].

[0097] In this embodiment, the difference between the feed power limit and the actual obtained feed power value is processed by power loop and proportional-integral method, and then by slope compensation to limit the obtained value to the range of [-3, 0], thus obtaining the above-mentioned feed power reference value.

[0098] In actual control, the range [-3, 0] of the aforementioned grid power reference value is segmented. When adjusting the grid power, limiting the output power of the photovoltaic power generation modules is preferred, as it reduces the impact on the control logic of the energy storage modules and the energy storage converter. However, if limiting the output power of the photovoltaic power generation modules and the discharge power of the energy storage modules still cannot meet the grid power limit requirements, then to ensure that the grid power does not exceed the limit, the output power of the inverter side port of the energy storage converter is limited, thereby fundamentally solving the problem of grid power exceeding the limit.

[0099] For example, if the grid power reference value meets the third preset reference range [-3, -2], then adjusting the power generation of the photovoltaic power generation module alone cannot meet the grid power limit, and it is necessary to further limit the discharge power of the energy storage module.

[0100] In this scenario, when the PI circuit output is in the range of [-3, -2], the PV output is in the range of [-2, -1], which, after limiting, becomes 0, meaning the PV power is limited to 0, and the PV output is shut down. Similarly, the maximum discharge power of the energy storage module is in the range of [-1, 0], which, after limiting, becomes 0, meaning the energy storage module's discharge power is limited to 0, and the energy storage module stops discharging. The maximum output power of the inverter terminal of the energy storage converter is in the range of [0, 1], thus limiting the inverter port. In this case, the maximum power output of the photovoltaic module, the maximum discharge power of the energy storage module, and the maximum output power of the inverter terminal all need to be limited to achieve the desired result.

[0101] Understandably, when the output of the PI circuit is within the range of [-2, 0], limiting the output power of the PV module and the discharge power of the energy storage module can satisfy the limitation on the grid power. According to the law of conservation of energy, the power generation of the PV module, the discharge power of the energy storage module, and the output power of the inverter satisfy the following constraints:

[0102] Pcs_Power=Pv_Power+Bat_Power.

[0103] Where Pcs_Power is the output power of the inverter output terminal of the energy storage converter, Pv_Power is the power generation power of the photovoltaic power generation module, and Bat_Power is the discharge power of the energy storage module.

[0104] When the voltage of the photovoltaic (PV) power generation module is within a controllable range, if the voltage is too high, the control loop of the PV power generation module will fail, and the power limit value of the PV power generation module will be invalid. The same applies to the energy storage module. However, even if the control of both the PV power generation module and the energy storage module fails, this application can still fundamentally solve the problem of grid power exceeding the limit by limiting the maximum output power of the inverter output terminal of the energy storage converter, ensuring that the final grid power is limited to below the set grid power limit.

[0105] In some embodiments of this application, the target power limit is determined based on the comparison result between the feed grid power reference value and the preset reference value range, including: determining the target offset value based on the comparison result; and performing slope compensation processing on the sum of the feed grid power reference value and the target offset value to obtain the target power limit.

[0106] In this embodiment, after obtaining the actual feed power value and the set feed power limit, the two are compared through a power loop, and a target offset value is determined based on the comparison result. This target offset value is used to instruct the control loop to adjust the feed power. To ensure that the control value can be executed without error, this application adds a proportional-integral (PI) control loop after the power loop. After the target offset value is processed by PI control, it is then processed by ramp compensation to obtain the aforementioned target power limit. The ramp compensation process ensures that the target power limit is within the range of [0, 1].

[0107] The embodiments of this application can achieve stable and reliable adjustment of the grid power, thereby limiting the grid power of the photovoltaic energy storage equipment to a suitable range and meeting the grid stability requirements.

[0108] In some embodiments of this application, a control device for a photovoltaic energy storage device is provided. The photovoltaic energy storage device includes a photovoltaic power generation module, an energy storage module, and an energy storage converter. The energy storage converter includes an inverter output terminal, which is used to output a grid-feed power signal.

[0109] Figure 3 Structural block diagrams of the control device for photovoltaic energy storage devices according to some embodiments of this application are shown, such as... Figure 3 As shown, the control device 300 includes: an acquisition module 302, used to acquire the grid power value of the grid power signal; a determination module 304, used to determine a grid power reference value based on the grid power value and the grid power limit; and to determine a target power limit based on the comparison result between the grid power reference value and a preset reference value range; wherein the target power limit includes at least one of the following: the maximum power output of the photovoltaic power generation module, the maximum discharge power of the energy storage module, and the maximum output power of the inverter output terminal; and a control module 306, used to control the output of the grid power signal of the photovoltaic energy storage device based on the target power limit.

[0110] In this embodiment, the photovoltaic energy storage device includes a photovoltaic (PV) power generation module, a power conversion system (PCS), and an energy storage module. The DC terminal of the power conversion system is electrically connected to the photovoltaic power generation module and the energy storage module, and the AC terminal of the power conversion system can be connected to the load and the power grid. Here, the inverter output terminal of the power conversion system is defined to output a grid feed signal to the power grid.

[0111] The purpose of this application is to ensure the stability of the power of the aforementioned feeder signal. To this end, this application acquires the feeder power value of the feeder signal output by the energy storage converter in real time and obtains the feeder power limit. For example, the feeder power limit issued by the grid-side meter can be obtained through the communication connection between the energy storage converter and the grid-side meter. For example, the feeder power limit can also be manually set by the user.

[0112] After obtaining the actual grid power value and the set grid power limit, the two are compared through the power loop, and the comparison result is determined. The comparison result reflects whether the power fed to the grid by the inverter output of the energy storage converter matches the set grid power limit. Based on the comparison result, the target power limit is determined. The target power limit is used to limit one or more of the power generation of the photovoltaic power generation module, the discharge power of the energy storage module, and the output power of the inverter output.

[0113] For example, photovoltaic energy storage devices can invert the electrical energy generated by photovoltaic power generation modules through an energy storage converter and output it to the grid. Therefore, the power generation of the photovoltaic power generation modules will affect the grid feed power. Simultaneously, in some scenarios, such as when the energy storage module is fully charged and the load demand is very low, the electrical energy stored in the energy storage module can also be inverted through the energy storage converter and output to the grid. In this case, the discharge power of the energy storage module will also affect the grid feed power. Therefore, the grid feed power can be regulated by adjusting the power generation of the photovoltaic power generation modules and the discharge power of the energy storage module.

[0114] In some cases, if the grid power still cannot meet the grid power limit after adjusting the power generation of photovoltaic power generation modules and the discharge power of energy storage modules, it is necessary to further adjust the output power of the inverter output terminal of the energy storage converter to fundamentally ensure that the output power of the inverter output terminal meets the grid power limit.

[0115] The embodiments of this application can achieve stable and reliable adjustment of the grid power, thereby limiting the grid power of the photovoltaic energy storage equipment to a suitable range and meeting the grid stability requirements.

[0116] In some embodiments of this application, optionally, determining a feeder power reference value based on the feeder power value and the feeder power limit includes: performing proportional-integral control processing and slope compensation processing on the difference between the feeder power limit and the feeder power value to obtain the feeder power reference value.

[0117] In this embodiment, the difference between the grid power limit and the actual obtained grid power value can reflect whether the grid power of the photovoltaic energy storage device meets the requirements. By determining the difference between the two through the power loop, power closed-loop control can be performed, which can enable the actual grid power to track the grid power limit, thereby improving grid efficiency while ensuring that the grid power is stable and does not exceed the limit.

[0118] After obtaining the power loop output, the output value is further processed by proportional-integral (PI) control and then by slope compensation to obtain the aforementioned feeder power reference value. This application uses power loop control based on the set feeder power limit and the actual collected feeder power value to enable the photovoltaic energy storage device to maximize feeder efficiency without exceeding the limits.

[0119] In some embodiments of this application, optionally, the range of the grid power reference value is [-3, 0]; the determining module is further configured to determine the maximum power output of the photovoltaic power generation module based on the grid power reference value when the grid power reference value meets the first preset reference value range; the control module is further configured to control the operation of the photovoltaic power generation module based on the maximum power output and control the energy storage converter to output the grid power signal; wherein, the first preset reference value range is [-1, 0].

[0120] In this embodiment of the application, the difference between the feed power limit and the actual obtained feed power value is processed by power loop and proportional integral, and then by slope compensation to limit the obtained value to the range of [-3, 0], thus obtaining the above-mentioned feed power reference value.

[0121] In actual control, the range [-3, 0] of the above-mentioned grid power reference value is segmented. When adjusting the grid power, limiting the output power of the photovoltaic power generation modules is preferred, which can reduce the impact on the control logic of the energy storage modules and the control logic of the energy storage converter.

[0122] For example, if the grid power reference value meets the first preset reference range [-1, 0], then only the power generation of the photovoltaic power generation module is adjusted, and the grid power value is limited by limiting the maximum power generation of the photovoltaic power generation module.

[0123] Specifically, when the output of the PI circuit is in the range of [-1, 0], the power output limit of the PV module is in the range of [0, 1], which can limit the power of the PV module. When the maximum power output is 0, it means that the power output of the PV module is 0, that is, the PV module does not output power. When the maximum power output is 1, it means that the power output of the PV module is not limited.

[0124] When the output power limit of the PV is within the range of [0, 1], the maximum discharge power of the energy storage module is within the range of [1, 2]. After limiting, the maximum discharge power of the energy storage module is 1, and therefore it is unrestricted. Similarly, the maximum output power of the inverter end of the energy storage converter is within the range of [2, 3]. After limiting, its value is also 1, so the inverter side is also unrestricted. In this case, limiting only the output power of the PV is sufficient to achieve the goal.

[0125] In this embodiment of the application, when the power of the feed grid exceeds the limit, the output power limit on the PV side is adjusted first, so that the power of the feed grid can be limited to a reasonable range, and the impact on the system is small.

[0126] In some embodiments of this application, optionally, the range of the grid power reference value is [-3, 0]; the determining module is further configured to determine the maximum power output of the photovoltaic power generation module and the maximum discharge power output of the energy storage module based on the grid power reference value when the grid power reference value meets the second preset reference value range; the control module is further configured to control the operation of the photovoltaic power generation module based on the maximum power output, control the discharge of the energy storage module based on the maximum discharge power output, and control the energy storage converter to output the grid power signal; wherein, the second preset reference value range is [-2, -1].

[0127] In this embodiment of the application, the difference between the feed power limit and the actual obtained feed power value is processed by power loop and proportional integral, and then by slope compensation to limit the obtained value to the range of [-3, 0], thus obtaining the above-mentioned feed power reference value.

[0128] In actual control, the range [-3, 0] of the aforementioned grid power reference value is segmented. When adjusting the grid power, limiting the output power of the photovoltaic (PV) modules is preferred to reduce the impact on the control logic of the energy storage modules and the energy storage converter. However, if limiting the output power of the PV modules still fails to meet the grid power limit requirements, or if the voltage of the PV modules exceeds the controllable range, causing the control loop of the PV modules to fail, then further adjustment of the discharge power of the energy storage modules is required.

[0129] For example, if the grid power reference value meets the second preset reference range [-2, -1], then adjusting the power generation of the photovoltaic power generation module alone cannot meet the grid power limit, and it is necessary to further limit the discharge power of the energy storage module.

[0130] When the output of the PI circuit is in the range of [-2, -1], the value of the PV circuit is in the range of [-1, 0]. After limiting, it becomes 0, meaning the power of the PV circuit is limited to 0, and the PV output is turned off. The maximum discharge power of the energy storage module is in the range of [0, 1], thus partially limiting the discharge power of the energy storage module. The maximum output power of the inverter end of the energy storage converter is in the range of [1, 2]. After limiting, its value is 1, therefore the inverter side is unrestricted. In this case, it is necessary to simultaneously limit the output power of the PV circuit and the discharge power of the energy storage module to achieve the desired result.

[0131] In this embodiment of the application, when the power of the grid feed exceeds the limit, the output power limit of the PV side is adjusted first. If adjusting only the output power limit of the PV side cannot meet the requirements, the discharge power of the battery module is further adjusted to ensure that the power of the grid feed is limited to a reasonable range.

[0132] In some embodiments of this application, optionally, the range of the grid power reference value is [-3, 0]; the determining module is further configured to determine the maximum power output of the photovoltaic power generation module, the maximum discharge power of the energy storage module, and the maximum output power of the inverter output terminal based on the grid power reference value when the grid power reference value meets the third preset reference value range; the control module is further configured to control the operation of the photovoltaic power generation module based on the maximum power output, control the discharge of the energy storage module based on the maximum discharge power, and control the output of the grid power signal of the energy storage converter based on the maximum output power of the inverter output terminal; wherein, the third preset reference value range is: [-3, -2].

[0133] In this embodiment, the difference between the feed power limit and the actual obtained feed power value is processed by power loop and proportional-integral method, and then by slope compensation to limit the obtained value to the range of [-3, 0], thus obtaining the above-mentioned feed power reference value.

[0134] In actual control, the range [-3, 0] of the aforementioned grid power reference value is segmented. When adjusting the grid power, limiting the output power of the photovoltaic power generation modules is preferred, as it reduces the impact on the control logic of the energy storage modules and the energy storage converter. However, if limiting the output power of the photovoltaic power generation modules and the discharge power of the energy storage modules still cannot meet the grid power limit requirements, then to ensure that the grid power does not exceed the limit, the output power of the inverter side port of the energy storage converter is limited, thereby fundamentally solving the problem of grid power exceeding the limit.

[0135] For example, if the grid power reference value meets the third preset reference range [-3, -2], then adjusting the power generation of the photovoltaic power generation module alone cannot meet the grid power limit, and it is necessary to further limit the discharge power of the energy storage module.

[0136] In this scenario, when the PI circuit output is in the range of [-3, -2], the PV output is in the range of [-2, -1], which, after limiting, becomes 0, meaning the PV power is limited to 0, and the PV output is shut down. Similarly, the maximum discharge power of the energy storage module is in the range of [-1, 0], which, after limiting, becomes 0, meaning the energy storage module's discharge power is limited to 0, and the energy storage module stops discharging. The maximum output power of the inverter terminal of the energy storage converter is in the range of [0, 1], thus limiting the inverter port. In this case, the maximum power output of the photovoltaic module, the maximum discharge power of the energy storage module, and the maximum output power of the inverter terminal all need to be limited to achieve the desired result.

[0137] Understandably, when the output of the PI circuit is within the range of [-2, 0], limiting the output power of the PV module and the discharge power of the energy storage module can satisfy the limitation on the grid power. According to the law of conservation of energy, the power generation of the PV module, the discharge power of the energy storage module, and the output power of the inverter satisfy the following constraints:

[0138] Pcs_Power=Pv_Power+Bat_Power.

[0139] Where Pcs_Power is the output power of the inverter output terminal of the energy storage converter, Pv_Power is the power generation power of the photovoltaic power generation module, and Bat_Power is the discharge power of the energy storage module.

[0140] When the voltage of the photovoltaic (PV) power generation module is within a controllable range, if the voltage is too high, the control loop of the PV power generation module will fail, and the power limit value of the PV power generation module will be invalid. The same applies to the energy storage module. However, even if the control of both the PV power generation module and the energy storage module fails, this application can still fundamentally solve the problem of grid power exceeding the limit by limiting the maximum output power of the inverter output terminal of the energy storage converter, ensuring that the final grid power is limited to below the set grid power limit.

[0141] In some embodiments of this application, the determining module is further configured to determine the target offset value based on the comparison result; and to perform slope compensation processing on the sum of the feed grid power reference value and the target offset value to obtain the target power limit value.

[0142] In this embodiment, after obtaining the actual feed power value and the set feed power limit, the two are compared through a power loop, and a target offset value is determined based on the comparison result. This target offset value is used to instruct the control loop to adjust the feed power. To ensure that the control value can be executed without error, this application adds a proportional-integral (PI) control loop after the power loop. After the target offset value is processed by PI control, it is then processed by ramp compensation to obtain the aforementioned target power limit. The ramp compensation process ensures that the target power limit is within the range of [0, 1].

[0143] The embodiments of this application can achieve stable and reliable adjustment of the grid power, thereby limiting the grid power of the photovoltaic energy storage equipment to a suitable range and meeting the grid stability requirements.

[0144] In some embodiments of this application, a control device for a photovoltaic energy storage device is provided. Figure 4 Structural block diagrams of the control device for photovoltaic energy storage devices according to some embodiments of this application are shown, such as... Figure 4 As shown, the control device 400 includes: a memory 402 for storing programs or instructions; and a processor 404 for executing programs or instructions to implement the steps of the control method for the photovoltaic energy storage device provided in any of the above embodiments. Therefore, it also includes all the beneficial effects of the control method for the photovoltaic energy storage device provided in any of the above embodiments, and will not be described again here to avoid repetition.

[0145] In some embodiments of this application, a readable storage medium is provided, on which a program or instructions are stored. When the program or instructions are executed by a processor, they implement the steps of the control method for the photovoltaic energy storage device provided in any of the above embodiments. Therefore, it also includes all the beneficial effects of the control method for the photovoltaic energy storage device provided in any of the above embodiments. To avoid repetition, it will not be described again here.

[0146] In some embodiments of this application, a photovoltaic energy storage device is provided, including a control device for the photovoltaic energy storage device as provided in any of the above embodiments; and / or a readable storage medium as provided in any of the above embodiments. Therefore, it also includes all the beneficial effects of the control device for 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, which will not be repeated here to avoid repetition.

[0147] The methods can be implemented in various ways depending on specific features and / or example applications. For example, these methods can be implemented by a combination of hardware, firmware, and / or software. For instance, in a hardware implementation, the processor can be implemented in 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, microcontrollers, microprocessors, electronic devices, other device units for performing the functions described above, and / or combinations thereof.

[0148] A computer-readable storage medium can be a tangible device that holds and stores instructions for use by an instruction execution device. A computer-readable storage medium can be 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, but is not limited thereto. A non-exhaustive list of more specific examples of computer-readable storage media includes: portable computer floppy disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable optical disc read-only memory (CD-ROM), digital universal disk (DVD), memory cards, floppy disks, encoding mechanical devices (e.g., punched cards or grooves with raised structures for recording instructions), and any suitable combination of the foregoing. The computer-readable storage medium used herein should not be construed as the transmission of signals themselves, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media, or electrical signals transmitted through wires.

[0149] In the description of this application, the term "multiple" refers to two or more. Unless otherwise expressly defined, the terms "upper," "lower," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. The terms "connection," "installation," "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0150] In the description of this application, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this application, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0151] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A control method of a photovoltaic energy storage device, characterized in that, The photovoltaic energy storage device includes a photovoltaic power generation assembly, an energy storage assembly, and an energy storage converter, the energy storage converter includes an inverter output end for outputting a grid electricity signal; the control method includes: obtaining a grid power value of the grid electricity signal; determining a grid power reference value according to the grid power value and a grid power limit value; determining a target power limit value based on a comparison result of the grid power reference value and a preset reference value interval; wherein the target power limit value includes at least one of the following: a maximum power generation value of the photovoltaic power generation assembly, a maximum discharge power value of the energy storage assembly, and a maximum output power value of the inverter output end; controlling the photovoltaic energy storage device to output the grid electricity signal based on the target power limit value.

2. The control method of a photovoltaic energy storage device according to claim 1, characterized in that, The determination of the grid power reference value according to the grid power value and the grid power limit value includes: performing proportional integral control processing and slope compensation processing on the difference between the grid power limit value and the grid power value to obtain the grid power reference value.

3. The control method of a photovoltaic energy storage device according to claim 1, characterized in that, The value range of the grid power reference value is [-3, 0]; The determination of the target power limit value based on the comparison result of the grid power reference value and the preset reference value interval includes: determining the maximum power generation value of the photovoltaic power generation assembly according to the grid power reference value when the grid power reference value meets a first preset reference value interval; The control of the photovoltaic energy storage device to output the grid electricity signal based on the target power limit value includes: controlling the photovoltaic power generation assembly to work based on the maximum power generation value, and controlling the energy storage converter to output the grid electricity signal. The first preset reference value interval is [-1, 0].

4. The control method of a photovoltaic energy storage device according to claim 1, characterized in that, The value range of the grid power reference value is [-3, 0]; The determination of the target power limit value based on the comparison result of the grid power reference value and the preset reference value interval includes: determining the maximum power generation value of the photovoltaic power generation assembly and the maximum discharge power value of the energy storage assembly according to the grid power reference value when the grid power reference value meets a second preset reference value interval; The control of the photovoltaic energy storage device to output the grid electricity signal based on the target power limit value includes: controlling the photovoltaic power generation assembly to work based on the maximum power generation value, controlling the energy storage assembly to discharge based on the maximum discharge power value, and controlling the energy storage converter to output the grid electricity signal. The second preset reference value interval is [-2, -1].

5. The method of controlling a photovoltaic energy storage device according to claim 1, wherein, The value range of the grid power reference value is [-3, 0]; The determination of the target power limit value based on the comparison result of the grid power reference value and the preset reference value interval includes: determining the maximum power generation value of the photovoltaic power generation assembly, the maximum discharge power value of the energy storage assembly, and the maximum output power value of the inverter output end according to the grid power reference value when the grid power reference value meets a third preset reference value interval; The control of the photovoltaic energy storage device to output the grid electricity signal based on the target power limit value includes: Controlling the photovoltaic power generation assembly to work based on the maximum generation power, controlling the energy storage assembly to discharge based on the maximum discharge power, and controlling the energy storage converter to output the grid electricity signal based on the maximum output power of the inverter output end; The third preset reference value interval is [-3, -2].

6. The control method of a photovoltaic energy storage device according to any one of claims 1 to 5, characterized in that, The target power limit value is determined based on a comparison result of the grid power reference value and a preset reference value interval, including: A target offset value is determined based on the comparison result; The sum of the grid power reference value and the target offset value is subjected to a ramp compensation process to obtain the target power limit value.

7. A control device for a photovoltaic energy storage device, characterized in that The photovoltaic energy storage device includes a photovoltaic power generation assembly, an energy storage assembly, and an energy storage converter, the energy storage converter includes an inverter output end, and the inverter output end is used to output a grid electricity signal; the control device includes: An acquisition module is configured to acquire a grid power value of the grid electricity signal; A determination module is configured to determine a grid power reference value based on the grid power value and a grid power limit value; and A target power limit value is determined based on a comparison result of the grid power reference value and a preset reference value interval, and the target power limit value includes at least one of the following: a maximum generation power of the photovoltaic power generation assembly, a maximum discharge power of the energy storage assembly, and a maximum output power of the inverter output end; A control module is configured to control the photovoltaic energy storage device to output the grid electricity signal based on the target power limit value.

8. A control device for a photovoltaic energy storage device, characterized in that The control device includes: A memory is configured to store programs or instructions; A processor is configured to execute the programs or instructions to implement the steps of the control method of the photovoltaic energy storage device according to any one of claims 1 to 6.

9. A readable storage medium, on which a program or instructions are stored, characterized in that, The programs or instructions are executed by the processor to implement the steps of the control method of the photovoltaic energy storage device according to any one of claims 1 to 6.

10. A photovoltaic energy storage device, characterized by, The control device includes: The control device of the photovoltaic energy storage device according to claim 7 or 8; And / or The readable storage medium according to claim 9.

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