Photovoltaic storage integrated system and energy control method

Abstract

The present invention provides an integrated photovoltaic and energy storage system and energy control method. The integrated photovoltaic and energy storage system includes: a photovoltaic and energy storage module, a stacked photovoltaic module, and an AC-DC module connected in parallel to a DC bus; the photovoltaic and energy storage module includes at least one set of photovoltaic and energy storage units, wherein the first photovoltaic panel in each photovoltaic and energy storage unit is connected to the first end of a first photovoltaic controller, the second end of the first photovoltaic controller is connected to the DC bus via a bidirectional DC-DC module, and the energy storage battery is connected to the second end of the first photovoltaic controller; the installed capacity of the photovoltaic and energy storage module is at least 0.8 times the load power; the stacked photovoltaic module converts light energy into electrical energy and provides it to the DC bus; the installed capacity of the stacked photovoltaic module is 0.8 to 1.2 times the load power; and the AC-DC module converts AC power provided by the power grid into DC power and provides it to the DC bus. The present invention effectively reduces bus voltage fluctuations, avoids photovoltaic power abandonment, and improves the utilization rate, power generation efficiency, and system reliability of photovoltaic power generation.

Description

Technical Field

[0001] The present invention relates to the field of new energy, and in particular to a photovoltaic-storage integrated system and an energy control method. Background Art

[0002] Green energy, also known as clean energy or renewable energy, refers to energy sources that have minimal environmental impact and low pollution emissions during production. These energy sources primarily include solar energy, wind energy, water energy (hydropower), biomass energy, and geothermal energy. Green energy is renewable, environmentally friendly, and low-carbon, making it a crucial energy option for addressing global climate change and achieving sustainable development.

[0003] As a major energy consumer, the communications industry faces immense pressure to conserve energy and reduce emissions. Traditional AC-to-solar systems suffer from multiple conversion levels, low power generation efficiency, and a long payback period. Against this backdrop, integrated photovoltaic and energy storage technology for communication base stations has emerged. By integrating photovoltaic power generation and energy storage systems, this technology enables energy self-sufficiency and green power supply for communication base stations. The photovoltaic power generation system utilizes clean, renewable solar energy to convert sunlight into electricity, providing a continuous power supply for communication base stations. Simultaneously, the energy storage system reduces electricity costs by shaving peak power and absorbing excess solar energy.

[0004] Although many base stations currently have energy storage or photovoltaic systems installed, they only use energy storage for peak-valley arbitrage or photovoltaics for DC-solar stacking. Furthermore, when using photovoltaics for DC-solar stacking, if the installed photovoltaic capacity exceeds the load, it can lead to significant bus voltage fluctuations. Therefore, when installing photovoltaics at base stations, to ensure the safety of the base station power supply system, most base stations install photovoltaic capacity less than the load power. This results in a waste of photovoltaic resources and reduces the return on photovoltaics.

[0005] How to propose an efficient, reliable and green communication base station energy solution has become one of the urgent problems to be solved by those skilled in the art.

[0006] It should be noted that the above technical background is merely provided to provide a clear and complete description of the technical solutions of the present invention and to facilitate understanding by those skilled in the art. Simply because these solutions are described in the technical background section of the present invention, it should not be assumed that the above technical solutions are well known to those skilled in the art. Summary of the Invention

[0007] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide an integrated photovoltaic and energy storage system and an energy control method to solve the problems of low efficiency and low reliability of the integrated photovoltaic and energy storage system in the prior art.

[0008] To achieve the above-mentioned and other related objectives, the present invention provides a photovoltaic-storage integrated system, comprising:

[0009] The optical storage module, stacked optical module and AC-DC module are connected in parallel to the DC bus;

[0010] The photovoltaic storage module includes at least one group of photovoltaic storage units, each photovoltaic storage unit includes a first photovoltaic panel, a first photovoltaic controller, an energy storage battery and a bidirectional DC-DC module, wherein the first photovoltaic panel is connected to the first end of the first photovoltaic controller, the second end of the first photovoltaic controller is connected to the DC bus via the bidirectional DC-DC module, and the energy storage battery is connected to the second end of the first photovoltaic controller; the installed capacity of the photovoltaic storage module is n times the load power, where n is a number greater than or equal to 0.8;

[0011] The stacked light module converts light energy into electrical energy and provides it to the DC bus; the installed capacity of the stacked light module is 0.8 to 1.2 times the load power;

[0012] The AC-DC module converts AC power provided by the power grid into DC power and provides the DC power to the DC bus.

[0013] Optionally, the stacked light module includes at least one group of stacked light units, each stacked light unit includes a second photovoltaic panel and a second photovoltaic controller, and the second photovoltaic panel is connected to the DC bus via the second photovoltaic controller.

[0014] To achieve the above-mentioned and other related objectives, the present invention further provides an energy control method, which is implemented based on the above-mentioned integrated photovoltaic and energy storage system. The energy control method at least includes:

[0015] During a first power demand period, the grid supplies power to the load on the DC bus, and the bidirectional DC-DC converter stores the power on the grid in the energy storage battery, where the charge capacity of the energy storage battery is determined by the power generated in the previous photovoltaic power generation cycle;

[0016] During the second power demand period, the stacked optical module and the optical storage module supply power to the load, the photovoltaic multi-generation energy in the optical storage module is stored in the energy storage battery, and the working state of the energy storage battery is dynamically adjusted according to the photovoltaic power generation based on the bidirectional DC-DC module, and the power supply priority of the stacked optical module is higher than that of the optical storage module;

[0017] During a third power demand period, the stacked optical module, the optical storage module, and the power grid supply power to the load, and the power supply priorities of the stacked optical module, the optical storage module, and the power grid decrease in sequence;

[0018] Among them, the first power demand period, the second power demand period and the third power demand period are set in a cycle in sequence; the first power demand period is a trough period, the second power demand period is a flat period, and the third power demand period is a peak period and / or a spike period.

[0019] Optionally, during the first power demand period, a predicted SOC of the energy storage battery is obtained based on the photovoltaic power generation and load power consumption in the previous photovoltaic power generation cycle, and charging is stopped when the energy storage battery is charged to the predicted SOC.

[0020] More optionally, the predicted SOC is the ratio of the difference between the battery nominal capacity and the amount of electricity provided to the energy storage battery by photovoltaic power generation in the previous photovoltaic power generation cycle to the battery nominal capacity.

[0021] Optionally, in the starting period of the second power demand period, the energy storage battery is controlled to discharge based on the bidirectional DC-DC module;

[0022] During the middle period of the second power demand period, determining whether the energy storage battery is discharged based on the relationship between the average photovoltaic power generation power and the load power on that day;

[0023] At the end of the second power demand period, the energy storage battery is controlled to be fully charged based on the bidirectional DC-DC module.

[0024] Optionally, when a third power demand period is provided between the first power demand period and the second power demand period,

[0025] During the start and middle periods of the second power demand period, determining whether the energy storage battery is discharged based on the relationship between the average photovoltaic power generation power and the load power on that day;

[0026] At the end of the second power demand period, the energy storage battery is controlled to be fully charged based on the bidirectional DC-DC module.

[0027] More optionally, the starting time period is set to 1 hour to 4 hours, and the ending time period is set to 1 hour to 4 hours.

[0028] More optionally, in the starting period and the middle period of the second power demand period, the method for determining whether the energy storage battery is discharged includes: if , the energy storage battery discharges; otherwise, the energy storage battery does not discharge;

[0029] in, is the average photovoltaic power generation power of the day; is the discharge judgment coefficient, ; is the load power of the day.

[0030] More optionally, when the middle period of the second power demand period is embedded in the first power demand period, during the first power demand period embedded in the second power demand period, the working status of the energy storage battery is judged based on the relationship between the average photovoltaic power generation power and the load power on that day.

[0031] More optionally, within the first power demand period embedded in the second power demand period, if , then the energy storage battery is controlled to discharge based on the bidirectional DC-DC module; if , the energy storage battery is controlled to charge based on the bidirectional DC-DC module; otherwise, the bidirectional DC-DC module does not work;

[0032] in, is the average photovoltaic power generation power of the day; is the load power of the day; is the discharge judgment coefficient, ; is the charging judgment coefficient, .

[0033] More optionally, when a second power demand period is set between the third power demand period and the first power demand period, the energy storage battery is discharged to a set SOC during the second power demand period between the third power demand period and the first power demand period, and the set SOC is not greater than 30%.

[0034] More optionally, when charging the energy storage battery, the bidirectional DC-DC conversion module controls the voltage of the energy storage battery, and the maximum limit value of the voltage loop output is set to positive, and the minimum limit value is set to negative; when discharging the energy storage battery, the bidirectional DC-DC conversion module controls the voltage of the DC bus, and the control voltage target value is greater than the output voltage value of the AC-DC conversion module, the maximum limit value of the voltage loop output is set to negative, and the minimum limit value is set to negative.

[0035] As described above, the integrated photovoltaic and energy storage system and energy control method of the present invention have the following beneficial effects:

[0036] 1. The photovoltaic output power of this invention can reach 2 to 4 times the load power, enabling direct photovoltaic power generation and storage. This ensures that every ray of sunlight is converted into clean electricity to the maximum extent possible, and in principle, there is no reverse flow to the power grid, setting a new benchmark for the application of green energy.

[0037] 2. This invention proposes a highly efficient, modular DC microgrid power supply system with an innovative system topology that simplifies energy conversion. When the sun is abundant, the power generated by the photovoltaic panels is directly input into the DC bus via an MPPT controller, and any excess power is directly stored in a storage battery. When photovoltaic power is insufficient or during peak electricity prices, power is automatically switched to the storage battery. If the stored power is also insufficient, the system seamlessly connects to the mains. This improves system efficiency while ensuring DC bus voltage stability. This innovative architecture lays a solid foundation for building a greener, smarter, and more sustainable energy ecosystem.

[0038] 3. The present invention uses a comprehensive energy management and scheduling algorithm to achieve seamless intelligent switching between photovoltaics, energy storage and city electricity, forming a three-source complementary power supply system, ensuring the system's power generation performance, and globally optimizing energy production, storage, distribution and consumption to achieve maximum energy utilization and optimal configuration. It can not only realize intelligent management of peak-shaving energy storage and peak-valley filling, but also ensure continuous and stable power supply without fear of any weather and time challenges, truly realizing the integration of "source, grid, load and storage". BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Shown is a structural schematic diagram of the integrated optical storage system of the present invention.

[0040] Figure 2 Shown is a schematic structural diagram of the bidirectional DC-DC module of the present invention.

[0041] Figure 3 Shown is a schematic diagram of the communication architecture of the integrated optical-storage system of the present invention.

[0042] Figure 4 This is shown as a first example of the energy control method of the present invention.

[0043] Figure 5 This is a second example of the energy control method of the present invention.

[0044] Figure 6 This is a third example of the energy control method of the present invention.

[0045] Figure 7 This is a fourth example of the energy control method of the present invention.

[0046] Component number description DETAILED DESCRIPTION

[0047] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0048] See also Figures 1 to 7 It should be noted that the diagrams provided in this embodiment are merely schematic illustrations of the basic concept of the present invention. Therefore, the diagrams only show components related to the present invention and are not drawn according to the number, shape, and size of components in actual implementation. In actual implementation, the type, quantity, and proportion of each component may be changed arbitrarily, and the component layout may also be more complex.

[0049] like Figure 1 As shown, the present invention provides an integrated photovoltaic and storage system 1, which includes: a photovoltaic and storage module 11, a stacked optical module 12 and an AC-DC module 13 connected in parallel to a DC bus BUS; and is used to power a DC load.

[0050] like Figure 1 As shown, the photovoltaic storage module 11 includes at least one group of photovoltaic storage units, and each group of photovoltaic storage units is connected in parallel to the DC bus BUS.

[0051] Specifically, in this embodiment, the solar-storage module 11 includes two solar-storage units, designated as a first solar-storage unit 11a and a second solar-storage unit 11b. Each solar-storage unit has the same structure. For example, the first solar-storage unit 11a includes a first photovoltaic panel 111, a first photovoltaic controller 112 (MPPT controller), an energy storage battery C1, and a bidirectional DC-DC converter 113. The first photovoltaic panel 111 converts solar energy into electrical energy. The first photovoltaic controller 112 is connected to the first photovoltaic panel 111 at its first terminal, controlling the panel 111 to output maximum power. The energy storage battery C1 is connected to the second terminal of the first photovoltaic controller 112 for energy storage. The bidirectional DC-DC converter 113 has one terminal connected to the second terminal of the first photovoltaic controller 112 and a second terminal connected to the DC bus (BUS), enabling bidirectional energy conversion between the energy storage battery C1 and the DC bus (BUS).

[0052] More specifically, if Figure 2 As shown, in this embodiment, the bidirectional DC-DC module 113 includes a voltage loop 113a and a current loop 113b. The voltage loop 113a is based on the control voltage feedback signal With the reference voltage given by the system The current reference value is obtained by limiting the current (limiting the maximum current) , voltage feedback signal The sampling value of the battery voltage or bus voltage is obtained through the switch; the current loop 113b is connected to the output end of the voltage loop 113a, based on the current feedback signal With current reference value The control voltage D of the switch (the switch control signal before correction) is calculated based on the difference between the feedback value and the reference value. The voltage loop 113a and the current loop 113b both include a difference operator and a proportional-integral (PI) controller. The difference operator subtracts the feedback value from a given value (a voltage reference value or a current reference value) to obtain a difference. The PI controller performs a proportional-integral operation on the difference to implement voltage or current loop control, thereby obtaining a corrected control variable D. As an example, a correction unit (not shown) may be provided at the output of the current loop. This correction unit is implemented using an adder. In actual use, it may also be implemented using an operator including, but not limited to, a subtractor, as needed. The correction unit may also be removed, and this is not limited to this embodiment.

[0053] In this example, when charging the energy storage battery C1, the bidirectional DC-DC module 113 controls the voltage of the energy storage battery C1, and the voltage loop output (i.e., the current reference value) ) The maximum limit value is set to positive and the minimum limit value is set to negative.

[0054] In this example, when the energy storage battery C1 is discharging, the bidirectional DC-DC module 113 controls the bus voltage Vbus, and the control voltage target value is greater than the output voltage value of the AC-DC module 13, and the voltage loop output maximum limit value is set to negative, and the minimum limit value is set to negative.

[0055] It should be noted that in actual use, the number of photovoltaic storage units is configured according to actual needs, so that the installed capacity of the photovoltaic storage module 11 is n times the load power, where n is a number greater than or equal to 0.8, including but not limited to 1, 1.2, 1.5, 2, 3, and 5. The load power can be set remotely, or the average load power can be calculated through sampling. In addition, each energy storage battery C1 can be configured as a single battery or as a series, parallel, or series-parallel combination of two or more batteries.

[0056] like Figure 1 As shown, the stacked optical module 12 converts light energy into electrical energy and provides it to the DC bus BUS.

[0057] Specifically, the stacked optical module 12 includes at least one set of stacked optical units, each connected in parallel to the DC bus (BUS). In this embodiment, the stacked optical module 12 includes two sets of stacked optical units, designated as a first stacked optical unit 12a and a second stacked optical unit 12b. Each stacked optical unit has the same structure. For example, the first stacked optical unit 12a includes a second photovoltaic panel 121 and a second photovoltaic controller 122 (MPPT controller). The second photovoltaic panel 121 converts solar energy into electrical energy. The first end of the second photovoltaic controller 122 is connected to the second photovoltaic panel 121, controlling the panel 121 to output maximum power. The second end of the second photovoltaic controller 122 is connected to the DC bus (BUS).

[0058] It should be noted that in actual use, the number of stacked light units is configured according to actual needs, and the installed capacity of the stacked light module 12 is configured to be 0.8 to 1.2 times the load power, including but not limited to 0.9, 1, and 1.1 times. The photovoltaic power generation of each stacked light unit can directly power the load, achieving optimal photoelectric conversion efficiency.

[0059] When the total photovoltaic power generation of the system exceeds the load power, the excess photovoltaic energy of the photovoltaic storage unit is first stored directly in the energy storage battery. The remaining photovoltaic energy of the photovoltaic storage unit is used to power the load together with the photovoltaic power generation energy of the stacked photovoltaic unit through the bidirectional DC-DC module. When the photovoltaic power generation power is less than the load power, and during the first or second power demand period, the energy stored in the energy storage battery is released through the bidirectional DC-DC module to power the load. This shows that the conversion of photovoltaic energy of the photovoltaic storage unit does not require the bidirectional DC-DC module to charge and discharge the battery as in traditional control, and the efficiency is also optimized.

[0060] Furthermore, because the photovoltaic capacity of the stacked photovoltaic unit is configured similarly to the load power, under high sunlight conditions, the photovoltaic power generation of the stacked photovoltaic unit can just meet the load consumption, while the photovoltaic power generation of the photovoltaic storage unit is entirely used to charge the energy storage battery. When the energy storage battery is fully charged, the photovoltaic controller of the photovoltaic storage unit will operate at a limited power level. However, when sunlight suddenly decreases, the photovoltaic power generation of the stacked photovoltaic unit is far from meeting the load consumption. The photovoltaic storage unit can then power the load together with the stacked photovoltaic unit through a bidirectional DC-DC converter. The bidirectional DC-DC converter then controls the bus voltage through a voltage loop. As a result, the bus voltage does not fluctuate significantly due to drastic changes in sunlight. The photovoltaic fluctuations are mainly absorbed by the energy storage unit's energy storage battery, greatly improving system stability and reliability.

[0061] The communication architecture of the optical storage integrated system 1 of the present invention is as follows Figure 3As shown, the remote monitoring module 14 is connected to the display screen 15 and controls the photovoltaic and energy storage integrated equipment (photovoltaic controller, bidirectional DC-DC module) in the communication base station through the central controller 16, and remotely sets the peak and valley charge and discharge time of the energy storage battery, the equalization charge voltage, the float charge voltage and other parameters of the energy storage battery.

[0062] The integrated photovoltaic and storage system of the present invention is highly intelligent, collects operating data in real time, and adaptively adjusts the operating mode according to the operating status without manual intervention, reducing operation and maintenance costs. The system has a high degree of integration and adopts an integrated design to reduce product energy consumption costs and achieve significant economic benefits. The system is highly secure, and each electrical equipment and system has multiple protections. The operating data is monitored in real time through a big data cloud platform, providing safe, clean, reliable, and cheap electricity for the stable operation of the system.

[0063] The present invention also provides an energy control method, which aims to formulate a reasonable charging and discharging plan based on the actual situation of the electricity market, the power demand of communication base stations, and the technical characteristics of the photovoltaic storage system, so as to achieve the goals of maximizing the use of photovoltaic energy, staggering energy storage, and saving energy and reducing emissions. The energy control method of the present invention is implemented based on the photovoltaic storage system 1 described above, and includes:

[0064] During the first power demand period, the grid supplies power to the loads on the DC bus BUS, and the bidirectional DC-DC converter stores the grid power in the energy storage battery. The charge capacity of the energy storage battery is determined by the power generated in the previous photovoltaic power generation cycle.

[0065] During the second power demand period, the stacked photovoltaic module and the photovoltaic storage module supply power to the load, the photovoltaic power generation in the photovoltaic storage module is stored in the energy storage battery, and the working state of the energy storage battery is dynamically adjusted according to the photovoltaic power generation based on the bidirectional DC-DC module, and the power supply priority of the stacked photovoltaic module is higher than that of the photovoltaic storage module;

[0066] During the third power demand period, the stacked optical module, the optical storage module, and the power grid supply power to the load, and the power supply priorities of the stacked optical module, the optical storage module, and the power grid decrease in sequence;

[0067] Among them, the first power demand period, the second power demand period and the third power demand period are set in sequence; the first power demand period is the trough period, the second power demand period is the flat period, and the third power demand period is the peak period and / or the spike period.

[0068] As a first example, Figure 4As shown, the 24 hours of a day are divided into three power demand periods, wherein the first power demand period (valley) starts from 24:00 and ends at 9:00, the second power demand period (flat) starts from 9:00 and ends at 16:00, and the third power demand period (peak / spike) starts from 16:00 and ends at 24:00. The start and end nodes of each period can be determined according to the actual power consumption situation in each region, and are not limited to this embodiment.

[0069] The first power demand period is generally set to the period of relatively low power consumption at night and in the morning. During the first power demand period, the photovoltaic panels basically do not generate electricity, the power consumption of the load is greatly reduced, and the electricity price is relatively low; at this time, the power grid supplies power to the load, and at the same time charges the energy storage battery C1 in the photovoltaic storage module 11 through the grid.

[0070] Specifically, as an example, during this charging phase, the predicted SOC of the energy storage battery is calculated based on the photovoltaic power generation and load power consumption during the previous photovoltaic power generation cycle T1. When the energy storage battery C1 reaches the predicted SOC, charging is stopped to limit the charging amount, thereby ensuring that the solar energy of the next photovoltaic power generation cycle is fully utilized and stored. The photovoltaic power generation cycle is the period of time during the day when photovoltaics convert solar energy into electrical energy (for example, from 9:00 to 17:00 every day). Furthermore, in this embodiment, the predicted SOC is the ratio of the difference between the battery's nominal capacity and the power provided to the energy storage battery by photovoltaics during the previous photovoltaic power generation cycle to the battery's nominal capacity, satisfying the following conditions:

[0071] (1);

[0072] in, To predict SOC, The amount of electricity that the photovoltaic power generation system charges to the energy storage battery during the last photovoltaic power generation cycle. The nominal energy of the energy storage battery (i.e., the kWh of the battery). In actual use, any method that can predict the battery SOC to reserve energy storage space for the next photovoltaic power generation cycle is applicable to the present invention, and is not limited to this embodiment.

[0073] Specifically, as an example, in this charging phase, the bidirectional DC-DC converter module 113 controls the energy storage battery C1, and the energy storage battery C1 is charged in an equalization charging mode, satisfying:

[0074] (2);

[0075] (3);

[0076] in, is the charging current of the energy storage battery; is the charging coefficient of the energy storage battery, , including but not limited to 1.2, 1.3, and 1.4; is the actual SOC of the energy storage battery (a number between 0 and 1); is the rated capacity of the energy storage battery (i.e. the number of Ah of the battery), is the end time of the first power demand period, is the current time, is the reference voltage given by the system, is the equalization charging voltage given by the system.

[0077] The second power demand period is set as a period during the day when electricity consumption is relatively low. During the second power demand period, when there is sufficient sunshine, the photovoltaic panels convert solar energy into electrical energy. Compared with the first power demand period, the amount of electricity consumed by the load increases and the electricity price increases. At this time, the electric energy generated by the stacked photoelectric module 12 is used to power the load first. When the electric energy provided by the stacked photoelectric module 12 is insufficient, it is supplemented by the photovoltaic storage module 11. The excess photovoltaic energy in the photovoltaic storage module 11 is stored in the energy storage battery C1, and the working state of the energy storage battery C1 is dynamically adjusted according to the photovoltaic power generation.

[0078] Specifically, in this embodiment, the second power demand period is divided into three periods, namely the starting period, the middle period, and the ending period. The duration of the starting period and the ending period is set to an empirical value, which can be different according to different regions. For example, it is set to 1 hour to 4 hours. As an example, the starting period is set to 2, 2.3, 2.5, 3, 3.2, 3.5 or 3.8 hours, and the ending period is set to 2, 2.5, 2.7, 3, 3.3, 3.5 or 3.7 hours; the period between the starting period and the ending period is the middle period. In this example, the starting stage starts from 9:00 and ends at 11:00, the middle period starts from 11:00 and ends at 14:00, and the ending period starts from 14:00 and ends at 16:00.

[0079] More specifically, during the initial period, the bidirectional DC-DC module 113 controls the energy storage battery C1 to discharge, so as to ensure that the energy storage battery C1 has sufficient capacity to absorb excess photovoltaic power generation and has the function of peak shaving and valley filling.

[0080] More specifically, during the intermediate period, the relationship between the average photovoltaic power generation and the load power of the day is used to determine whether the energy storage battery C1 is discharged. The average photovoltaic power generation of the day is the average photovoltaic power generation from the start of photovoltaic power generation to the current time. Assuming that photovoltaic power generation starts at 6:00 and the current time is 11:00, the average photovoltaic power generation of the day is the average power from 6:00 to 11:00 (5 hours). Similarly, the load power of the day is the load power from the start of electricity consumption to the current time. As an example, the method for determining whether the energy storage battery is discharged includes: if , then the energy storage battery C1 is controlled to discharge, otherwise the energy storage battery C1 is controlled not to discharge. is the average power of photovoltaic power generation on that day; is the discharge judgment coefficient, , including but not limited to 0.6, 0.8, 1, 1.3, 1.5, 1.7, 1.9; is the load power of the day.

[0081] More specifically, during the end period, the bidirectional DC-DC module 113 controls the energy storage battery C1 to be fully charged in preparation for peak discharge.

[0082] The third power demand period is set to the evening and nighttime, when electricity consumption is relatively high. During this period, the photovoltaic panels may only generate electricity in the initial stage and not during the rest of the period, significantly increasing load power consumption and raising electricity prices. During this period, the load is powered by the energy generated by the stacked photovoltaic module 12, followed by the energy stored in the photovoltaic storage module 11. Any shortfall is supplemented by the grid. During this process, the energy storage battery C1 in the photovoltaic storage module 11 is discharged.

[0083] As a second example, a third power demand period is provided between the first power demand period and the second power demand period. Figure 5 As shown, the 24 hours of a day are divided into four power demand periods, wherein the first power demand period (valley) starts from 23:00 and ends at 8:00, the first third power demand period (peak / spike) starts from 8:00 and ends at 11:00, the second power demand period (flat) starts from 11:00 and ends at 16:00, and the second third power demand period (peak / spike) starts from 16:00 and ends at 23:00. The start and end nodes of each period can be determined according to the actual power consumption situation in each region, and are not limited to this embodiment.

[0084] Specifically, the working principles of the first power demand period and each third power demand period are the same as those in the first example, and are not described in detail here.

[0085] Specifically, during the first third power demand period, the stacked photovoltaic module 12, the photovoltaic storage module 11, and the power grid supply power to the load in descending order of power supply priority, and the energy storage battery C1 is controlled by the bidirectional DC-DC module 113 to discharge. At this time, since the energy storage battery C1 has been discharged before the second power demand period, and storage space has been reserved, there is no need to perform a discharge operation at the beginning of the second power demand period. The beginning and middle periods of the second power demand period are both based on the relationship between the average photovoltaic power generation and the load power of the day to determine whether the energy storage battery C1 is discharged; at the end of the second power demand period, the bidirectional DC-DC module 113 controls the energy storage battery C1 to be fully charged. The specific method is described above and will not be repeated here.

[0086] As a third example, based on the first example or the second example, a first power demand period is further provided in the middle period of the second power demand period. In this example, taking the first power demand period added on the basis of the first example as an example, Figure 6 As shown, 24 hours a day is divided into five power demand periods, wherein the first power demand period (valley) starts from 24:00 and ends at 6:00, the second power demand period (flat) starts from 6:00 to 12:00, and then from 14:00 to 16:00, the third first power demand period (valley) starts from 12:00 to 14:00, and the third power demand period (peak / spike) starts from 16:00 to 24:00. The start and end nodes of each period can be determined according to the actual power consumption situation in each region, and are not limited to this embodiment.

[0087] Specifically, the working principles of the first first power demand period and the third power demand period are the same as those in the first example; the second first power demand period is embedded in the middle period of the second power demand period, and the second power demand period is divided into an initial stage, an intermediate stage and an ending stage; the specific working principles are the same as those in the first example and will not be elaborated here.

[0088] Specifically, during the second first power demand period, when the photovoltaic power generation is relatively large, the energy storage battery C1 performs a charging operation; when the photovoltaic power generation is relatively low, the energy storage battery C1 performs a discharging operation. In this example, the photovoltaic power generation is judged based on the relationship between the average photovoltaic power generation and the load power on that day, and then the working state of the energy storage battery C1 is determined. More specifically, if , then the bidirectional DC-DC module 113 controls the energy storage battery C1 to discharge. , the bidirectional DC-DC module 113 controls the energy storage battery C1 to charge; further, in this example, the bidirectional DC module 113 controls the energy storage battery C1 to charge in an equalizing charging mode, satisfying the above-mentioned relationship formulas (2)-(3).

[0089] As a fourth example, based on the first example, the second example or the third example, a second power demand period is further provided between the third power demand period and the first power demand period. In this example, taking the second example as an example, Figure 7 As shown, the 24 hours of a day are divided into five power demand periods, wherein the first power demand period (valley) starts from 23:00 and ends at 8:00, the first third power demand period (peak) starts from 8:00 and ends at 11:00, the first second power demand period (flat) starts from 11:00 and ends at 16:00, the second third power demand period (peak / spike) starts from 16:00 and ends at 21:00, and the second second power demand period (flat) starts from 21:00 and ends at 23:00. The start and end nodes of each period can be determined according to the actual power consumption situation in each region, and are not limited to this embodiment.

[0090] Specifically, the operating principles of the first power demand period, the first second power demand period, and each third power demand period are the same as those in the second example and are not detailed here. During the second second power demand period, the bidirectional DC-DC converter 113 controls the energy storage battery C1 to continue discharging until the energy storage battery C1 reaches a set state of charge (SOC). The set SOC can be set according to actual needs. As an example, the set SOC is no greater than 30%, including but not limited to 25%, 20%, 15%, and 10%. If the power provided by the energy storage battery C1 is insufficient, it is supplemented by the grid to ensure normal power supply to the load.

[0091] In the present invention, during the first power demand period, the bidirectional DC-DC converter module 113 controls the voltage of the energy storage battery C1. During other periods, including but not limited to the second and third power demand periods, the bidirectional DC-DC converter module 113 controls the voltage on the DC bus BUS or the voltage of the energy storage battery C1. This is not detailed here.

[0092] It should be noted that the setting of trough, flat and peak periods is determined by the power department based on the electricity consumption in each region.

[0093] In summary, the present invention provides an integrated photovoltaic and storage system and an energy control method, wherein the integrated photovoltaic and storage system includes: a photovoltaic and storage module, a stacked photovoltaic module and an AC-DC module connected in parallel on a DC bus; the photovoltaic and storage module includes at least one group of photovoltaic and storage units, each photovoltaic and storage unit includes a first photovoltaic panel, a first photovoltaic controller, an energy storage battery and a bidirectional DC-DC module, wherein the first photovoltaic panel is connected to the first end of the first photovoltaic controller, the second end of the first photovoltaic controller is connected to the DC bus via the bidirectional DC-DC module, and the energy storage battery is connected to the second end of the first photovoltaic controller; the installed capacity of the photovoltaic and storage module is n times the load power, where n is a natural number greater than or equal to 0.8; the stacked photovoltaic module converts light energy into electrical energy and provides it to the DC bus; the installed capacity of the stacked photovoltaic module is 0.8~1.2 times the load power; the AC-DC module converts AC power provided by the power grid into DC power and provides it to the DC bus. The present invention limits the capacity of the battery in advance by predicting the SOC, and then through multiple discharges, while satisfying the peak shaving and valley filling function, uses the photovoltaic prediction function to further adjust the battery capacity to ensure that photovoltaic power generation is fully utilized, greatly reducing the occurrence of abandoned light phenomenon, and improving the utilization rate of photovoltaic power generation. By combining DC superposition with energy storage, the excess electricity generated by photovoltaics is stored in the energy storage battery and utilized, thereby reducing the fluctuation of the bus voltage, avoiding the phenomenon of photovoltaic abandoned light, and improving the photovoltaic power generation efficiency and system reliability. Therefore, the present invention effectively overcomes the various shortcomings of the existing technology and has high industrial utilization value.

[0094] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A photovoltaic storage integrated system, characterized in that: The integrated optical storage system includes: The optical storage module, stacked optical module and AC-DC module are connected in parallel to the DC bus; The photovoltaic storage module includes at least one group of photovoltaic storage units, each photovoltaic storage unit includes a first photovoltaic panel, a first photovoltaic controller, an energy storage battery and a bidirectional DC-DC module, wherein the first photovoltaic panel is connected to the first end of the first photovoltaic controller, the second end of the first photovoltaic controller is connected to the DC bus via the bidirectional DC-DC module, and the energy storage battery is connected to the second end of the first photovoltaic controller; the installed capacity of the photovoltaic storage module is n times the load power, where n is a number greater than or equal to 0.8; The stacked light module converts light energy into electrical energy and provides it to the DC bus; the installed capacity of the stacked light module is 0.8 to 1.2 times the load power; the stacked light module includes at least one set of stacked light units, each stacked light unit includes a second photovoltaic panel and a second photovoltaic controller, and the second photovoltaic panel is connected to the DC bus via the second photovoltaic controller; The AC to DC module converts the AC power provided by the power grid into DC power and provides it to the DC bus; During a first power demand period, the power grid supplies power to the load on the DC bus, and the bidirectional DC-DC converter stores the power on the power grid in the energy storage battery, wherein the charge capacity of the energy storage battery is determined by the photovoltaic power generation in the previous photovoltaic power generation cycle; During a second power demand period, the stacked optical module and the optical storage module supply power to the load, the photovoltaic multi-generation energy in the optical storage module is stored in the energy storage battery, and the working state of the energy storage battery is dynamically adjusted according to the photovoltaic power generation based on the bidirectional DC-DC module, and the power supply priority of the stacked optical module is higher than that of the optical storage module; During a third power demand period, the stacked optical module, the optical storage module, and the power grid supply power to the load, and the power supply priorities of the stacked optical module, the optical storage module, and the power grid decrease in sequence; Among them, the first power demand period, the second power demand period and the third power demand period are set in a cycle in sequence; the first power demand period is a trough period, the second power demand period is a flat period, and the third power demand period is a peak period and / or a spike period.

2. The integrated photovoltaic and storage system according to claim 1, characterized in that: During the first power demand period, a predicted SOC of the energy storage battery is obtained based on the photovoltaic power generation and load power consumption in the previous photovoltaic power generation cycle, and charging of the energy storage battery is stopped when the energy storage battery is charged to the predicted SOC.

3. The integrated optical-storage system according to claim 2, characterized in that: The predicted SOC is the ratio of the difference between the battery nominal capacity and the amount of electricity provided to the energy storage battery by photovoltaic power generation in the previous photovoltaic power generation cycle to the battery nominal capacity.

4. The integrated photovoltaic and storage system according to claim 1, characterized in that: At the start of the second power demand period, controlling the energy storage battery to discharge based on the bidirectional DC-DC module; During the middle period of the second power demand period, determining whether the energy storage battery is discharged based on the relationship between the average photovoltaic power generation power and the load power on that day; At the end of the second power demand period, the energy storage battery is controlled to be fully charged based on the bidirectional DC-DC module.

5. The integrated optical storage system according to claim 1, characterized in that: When a third power demand period is provided between the first power demand period and the second power demand period, During the start and middle periods of the second power demand period, determining whether the energy storage battery is discharged based on the relationship between the average photovoltaic power generation power and the load power on that day; At the end of the second power demand period, the energy storage battery is controlled to be fully charged based on the bidirectional DC-DC module.

6. The integrated optical-storage system according to claim 4 or 5, characterized in that: The starting time period is set to 1 hour to 4 hours, and the ending time period is set to 1 hour to 4 hours.

7. The integrated optical-storage system according to claim 4 or 5, characterized in that: In the starting period and the middle period of the second power demand period, the method for determining whether the energy storage battery is discharged includes: if , the energy storage battery discharges; otherwise, the energy storage battery does not discharge; in, is the average photovoltaic power generation power of the day; is the discharge judgment coefficient, ; is the load power of the day.

8. The integrated optical-storage system according to claim 4 or 5, characterized in that: When the middle period of the second power demand period is embedded in the first power demand period, during the first power demand period embedded in the second power demand period, the working status of the energy storage battery is judged according to the relationship between the average photovoltaic power generation power and the load power of the day.

9. The integrated optical-storage system according to claim 8, characterized in that: In the first power demand period embedded in the second power demand period, if , then the energy storage battery is controlled to discharge based on the bidirectional DC-DC module; if , the energy storage battery is controlled to charge based on the bidirectional DC-DC module; otherwise, the bidirectional DC-DC module does not work; in, is the average photovoltaic power generation power of the day; is the load power of the day; is the discharge judgment coefficient, ; is the charging judgment coefficient, .

10. The integrated photovoltaic and storage system according to claim 4 or 5, characterized in that: When a second power demand period is set between the third power demand period and the first power demand period, the energy storage battery is discharged to a set SOC in the second power demand period between the third power demand period and the first power demand period, and the set SOC is not greater than 30%.

11. The integrated optical-storage system according to any one of claims 1 to 5, characterized in that: When charging the energy storage battery, the bidirectional DC-DC conversion module controls the voltage of the energy storage battery, and the maximum limit value of the voltage loop output is set to positive, and the minimum limit value is set to negative; when discharging the energy storage battery, the bidirectional DC-DC conversion module controls the voltage of the DC bus, and the control voltage target value is greater than the output voltage value of the AC-DC conversion module, and the maximum limit value of the voltage loop output is set to negative, and the minimum limit value is set to negative.

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