Sustainable power supply method, device and equipment for optical storage box transformer substation system, and medium

Abstract

The invention relates to the technical field of box transformer substation control, and discloses a sustainable power supply method, device and equipment for an optical storage box transformer substation system and a medium, and the method comprises the steps: obtaining a photovoltaic current, a load rated current, an energy storage maximum current, and an energy storage charge state; the relation among the photovoltaic current, the load rated current and the maximum energy storage current and the relation between the energy storage charge state and the normal charge state range are determined, and the maximum energy storage current is the maximum charging and discharging current of the energy storage module in the current charge state; and determining a power supply strategy of the optical storage box transformer substation system according to the relationship among the currents and the energy storage charge state. According to the invention, through monitoring each current parameter of the direct current side in the optical storage box transformer substation system, the power supply strategy of the optical storage box transformer substation system is dynamically adjusted according to the relation between each current, the optimal distribution of energy is ensured, the light abandoning phenomenon of photovoltaic power generation is reduced to the greatest extent, the energy utilization efficiency is improved, and the energy utilization rate is improved. Efficient transmission, distribution and sustainable power supply of electric power are realized, and stable operation of the system is ensured.

Description

Technical Field

[0001] The present invention relates to the field of box-type transformer control technology, and in particular to a sustainable power supply method, device, equipment and medium for a photovoltaic storage box-type transformer system. Background Art

[0002] As the proportion of new energy generation such as wind power and photovoltaic power generation connected to the power system will increase significantly, improving the efficiency of new energy generation and reducing operation and maintenance costs have become urgent problems and research hotspots that need to be solved. Distributed new energy power generation technology represents a revolutionary energy production model. By installing decentralized, small-scale new energy power generation devices, it can become a way to power existing equipment. This distributed model has become one of the main trends in the development of future power grids. The box-type transformer device of the conventional AC system has an uninterruptible power supply, which can provide short-term power supply for the secondary circuit of the box-type transformer system and the corresponding box-type transformer load. However, in the case of extreme main grid failure to feed power, the box-type transformer secondary equipment (including monitoring, measurement, communication, etc.) is very likely to lose energy supply and lose function, which brings great difficulties to the overall dispatching, operation and maintenance and monitoring of the power grid area.

[0003] Among the existing methods, consideration has been given to using a separate energy storage battery or a photovoltaic system and an energy storage battery to solve the secondary power consumption problem of the box transformer. However, these methods often adopt a mode of direct connection between photovoltaic panels and batteries. Although the direct connection mode is simple, it has many disadvantages in practical applications and lacks fine control over the flow of energy. Since the light intensity directly affects the power generation of photovoltaic panels, when the photovoltaic panels generate excess power, the excess electricity cannot be stored in time. Conversely, when the photovoltaic panels generate insufficient power, the stored electricity cannot be used efficiently. In this case, it is not only easy to cause a waste of solar energy, but also lead to unstable power supply in the secondary power system, and the potential of the photovoltaic system cannot be fully utilized. At the same time, intervention control in the event of a fault is not considered, and energy storage batteries are prone to energy waste. Summary of the invention

[0004] In view of this, the present invention provides a sustainable power supply method, device, equipment and medium for a photovoltaic storage box transformer system to solve the problem of how to use distributed photovoltaics to achieve sustainable power supply for a photovoltaic storage box transformer system.

[0005] In a first aspect, the present invention provides a sustainable power supply method for a photovoltaic storage box transformer system, wherein the photovoltaic storage box transformer system comprises: a transformer module, a photovoltaic panel, a photovoltaic storage inverter, an energy storage module, a basic load, and a DC bus, wherein the photovoltaic panel, the energy storage module, and the basic load are respectively connected to the DC side of the photovoltaic storage inverter through the DC bus, and the AC side of the photovoltaic storage inverter is connected to the power grid through the transformer module, and the method comprises: Obtain the photovoltaic current, load rated current, energy storage maximum current, and energy storage charge state, and determine the relationship between the photovoltaic current, load rated current, and energy storage maximum current, as well as the relationship between the energy storage charge state and the normal charge state range. The energy storage maximum current is the maximum charge and discharge current of the energy storage module under the current charge state; The power supply strategy of the photovoltaic-storage box-type transformer system is determined based on the relationship between the photovoltaic current, the load rated current, the maximum energy storage current, and the relationship between the energy storage charge state and the normal charge state range.

[0006] The sustainable power supply method for the photovoltaic power storage box-transformer system provided by the present invention monitors various current parameters on the DC side of the photovoltaic power storage box-transformer system, and dynamically adjusts the power supply strategy of the photovoltaic power storage box-transformer system according to the relationship between the various current parameters, thereby ensuring the optimal distribution of energy flow, minimizing the phenomenon of photovoltaic power generation abandonment, improving energy utilization efficiency, and realizing efficient transmission, distribution and sustainable power supply of electricity, so as to ensure the stable operation of the system.

[0007] In an optional embodiment, the method further includes: Obtain energy storage current, load current and the collection point current on the DC side of the photovoltaic storage inverter; According to the relationship between the collection point current on the DC side of the photovoltaic storage inverter and the photovoltaic current, load current, and energy storage current, it is determined whether the photovoltaic storage box transformer system has a DC fault; If a DC fault occurs, the power supply lines from the photovoltaic panels and energy storage modules in the photovoltaic-storage box-to-load system to the load will be cut off.

[0008] In an optional implementation, judging whether a DC fault occurs according to the relationship between the collection point current on the DC side of the photovoltaic storage inverter and the photovoltaic current, the load current, and the energy storage current includes: If the current at the collection point on the DC side of the photovoltaic storage inverter is equal to the sum of the photovoltaic current, load current, and energy storage current, then there is no DC fault in the photovoltaic storage box transformer system; If the collection point current on the DC side of the photovoltaic storage inverter is not equal to the sum of the photovoltaic current, load current, and energy storage current, a DC fault occurs in the photovoltaic storage box transformer system.

[0009] The sustainable power supply method for the photovoltaic storage box-to-transformer system provided by the present invention determines the operating status of the photovoltaic storage box-to-transformer system by real-time monitoring and comparison of the sum of the photovoltaic current, load current, and energy storage current with the current of the DC side collection point of the photovoltaic storage inverter, and identifies possible faults in the system, so as to take corresponding maintenance and repair measures in time to avoid energy loss caused by the expansion or long-term existence of the fault, reduce unnecessary energy consumption of the energy storage battery under abnormal conditions, maximize the overall energy efficiency of the system, and realize efficient and stable operation of the photovoltaic storage system.

[0010] In an optional implementation, the power supply strategy of the photovoltaic storage box transformer system is determined according to the relationship between the photovoltaic current, the load rated current, the maximum energy storage current, and the relationship between the energy storage charge state and the normal charge state range, including: If the photovoltaic current is greater than the rated current of the load, the electricity generated by the photovoltaic panel is used to power the photovoltaic storage box transformer system, and the part of the photovoltaic current that is greater than the rated current of the load is used to charge the energy storage module; If the charge state of the energy storage module reaches the upper limit of the normal charge state range, the part of the photovoltaic current that is greater than the rated current of the load enters the grid through the photovoltaic storage inverter and transformer module.

[0011] The sustainable power supply method for the photovoltaic storage box transformer system provided by the present invention directly utilizes photovoltaic power generation to power the load of the photovoltaic storage box transformer system when there is too much photovoltaic power generation, thereby improving energy utilization. The excess electric energy of photovoltaic power generation is used to charge the energy storage module or enter the power grid, thereby maximizing the utilization of photovoltaic power generation, reducing the phenomenon of photovoltaic power generation abandonment, and realizing efficient transmission and distribution of electricity.

[0012] In an optional implementation, the power supply strategy of the photovoltaic storage box transformer system is determined according to the relationship between the photovoltaic current, the load rated current, the maximum energy storage current, and the relationship between the energy storage charge state and the normal charge state range, including: If the photovoltaic current is less than the rated current of the load, and the maximum energy storage current is greater than the difference between the photovoltaic current and the rated current of the load, the electricity generated by the photovoltaic panels and the electricity stored in the energy storage module are used together to power the photovoltaic storage box transformer system.

[0013] The sustainable power supply method for the photovoltaic storage box-type transformer system provided by the present invention realizes efficient energy flow between photovoltaic power generation and energy storage modules when photovoltaic power generation is insufficient to support the basic operation of the photovoltaic storage box-type transformer system, preferentially calls the electric energy of the energy storage module, reduces dependence on the power grid, improves the independence and reliability of the secondary circuit of the box-type transformer system, ensures that photovoltaic power generation is fully utilized, and realizes efficient and stable operation of the photovoltaic storage box-type transformer system.

[0014] In an optional implementation, the power supply strategy of the photovoltaic storage box transformer system is determined according to the relationship between the photovoltaic current, the load rated current, the maximum energy storage current, and the relationship between the energy storage charge state and the normal charge state range, including: If the photovoltaic current is less than the rated current of the load, the maximum energy storage current is not greater than the difference between the photovoltaic current and the rated current of the load, and the energy storage charge state is within the normal charge state range, the power of the grid, the power of the energy storage module, and the power generated by the photovoltaic panels are used to power the photovoltaic storage box transformer system.

[0015] The sustainable power supply method for the photovoltaic storage box transformer system provided by the present invention mainly utilizes the electric energy of the power grid and the energy storage module to power the photovoltaic storage box transformer system when the photovoltaic power generation is too small and the current that can be provided by the energy storage module is also very small, and the electric energy in the photovoltaic power generation and the energy storage module cannot meet the load demand, thereby achieving sustainable power supply and maintaining stable operation of the photovoltaic storage box transformer system.

[0016] In an optional implementation, the power supply strategy of the photovoltaic storage box transformer system is determined according to the relationship between the photovoltaic current, the load rated current, the maximum energy storage current, and the relationship between the energy storage charge state and the normal charge state range, including: If the photovoltaic current is less than the rated current of the load and the energy storage charge state is less than the lower limit of the normal charge state range, the electricity in the grid is used to power the photovoltaic storage box transformer system.

[0017] The sustainable power supply method for the photovoltaic storage box transformer system provided by the present invention fully utilizes the power grid to supply power to the load of the photovoltaic storage box transformer system when the photovoltaic power generation is too small, the current that the energy storage module can provide is also very small, and the charge state of the energy storage module is too low, so as to compensate for the influence of light fluctuations, ensure stable power supply, avoid safety hazards and economic losses caused by power interruptions, and accurately manage the charging and discharging process of the energy storage module to avoid overcharging and over-discharging, thereby extending the service life of the energy storage module.

[0018] In a second aspect, the present invention provides a sustainable power supply device for a photovoltaic storage box transformer system, wherein the photovoltaic storage box transformer system comprises: a transformer module, a photovoltaic panel, a photovoltaic storage inverter, an energy storage module, a basic load, and a DC bus. The photovoltaic panel, the energy storage module, and the basic load are respectively connected to the DC side of the photovoltaic storage inverter through the DC bus, and the AC side of the photovoltaic storage inverter is connected to the power grid through the transformer module. The device comprises: The data acquisition module is used to obtain the photovoltaic current, the rated load current, the maximum energy storage current, and the energy storage charge state, and determine the relationship between the photovoltaic current, the rated load current, and the maximum energy storage current, and the relationship between the energy storage charge state and the normal charge state range. The maximum energy storage current is the maximum charge and discharge current of the energy storage module under the current charge state; The power supply strategy determination module is used to determine the power supply strategy of the photovoltaic storage box transformer system based on the relationship between the photovoltaic current, the load rated current, the maximum energy storage current, and the relationship between the energy storage charge state and the normal charge state range.

[0019] In a third aspect, the present invention provides a computer device, comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the method of the first aspect or any corresponding embodiment thereof by executing the computer instructions.

[0020] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to cause a computer to execute the method of the first aspect or any corresponding embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 is a structural schematic diagram of a photovoltaic storage box-type transformer system in a sustainable power supply method of a photovoltaic storage box-type transformer system according to an embodiment of the present invention; Figure 2 is a flow chart of a sustainable power supply method for a photovoltaic storage box transformer system according to an embodiment of the present invention; Figure 3 1. It is a schematic diagram of the energy control flow in the sustainable power supply method of the photovoltaic storage box transformer system according to an embodiment of the present invention; Figure 4 is a flow chart of another sustainable power supply method of a photovoltaic storage box transformer system according to an embodiment of the present invention; Figure 5 Schematic diagram of control signals for charging and discharging an energy storage module in a sustainable power supply method for a photovoltaic storage box transformer system according to an embodiment of the present invention; Figure 6 is a schematic diagram of changes in various currents in a specific simulation embodiment of a sustainable power supply method for a photovoltaic storage box transformer system according to an embodiment of the present invention; Figure 7 is a structural block diagram of a sustainable power supply device of a photovoltaic storage box transformer system according to an embodiment of the present invention; Figure 8 It is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0024] An embodiment of the present invention provides a sustainable power supply method for a photovoltaic power storage box transformer system, which monitors various current parameters on the DC side of the photovoltaic power storage box transformer system and dynamically adjusts the power supply strategy of the photovoltaic power storage box transformer system according to the relationship between the various current parameters, so as to achieve sustainable power supply for the photovoltaic power storage box transformer system and realize efficient and stable operation.

[0025] According to an embodiment of the present invention, an embodiment of a sustainable power supply method for a photovoltaic storage box transformer system is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0026] In this embodiment, a sustainable power supply method for a photovoltaic storage box transformer system is provided, which can be used in the above-mentioned computer system, such as Figure 1 As shown, the photovoltaic storage box transformer system includes: a transformer module, a photovoltaic panel, a photovoltaic storage inverter, an energy storage module, a basic load, and a DC bus. The photovoltaic panel, the energy storage module, and the basic load are respectively connected to the DC side of the photovoltaic storage inverter through the DC bus, and the AC side of the photovoltaic storage inverter is connected to the power grid through the transformer module. The structural composition of the photovoltaic storage box transformer system is a mature existing technology and will not be repeated here. Figure 2 is a flow chart of a sustainable power supply method for a photovoltaic storage box transformer system according to an embodiment of the present invention. Figure 2 As shown, the process includes the following steps: Step S101, obtaining the photovoltaic current, the load rated current, the maximum energy storage current, and the energy storage charge state, and determining the relationship between the photovoltaic current, the load rated current, and the maximum energy storage current, and the relationship between the energy storage charge state and the normal charge state range, wherein the maximum energy storage current is the maximum charge and discharge current of the energy storage module under the current charge state.

[0027] Specifically, the photovoltaic storage box transformer is based on the traditional box transformer, adding photovoltaic panels, photovoltaic storage inverters, and energy storage modules (generally energy storage batteries), and connecting them with the existing secondary circuit to achieve multi-power supply coordination of the secondary circuit, improve power supply reliability, make full use of solar energy resources, reduce dependence on traditional electricity, and improve energy utilization. The existing secondary circuit refers to the load of the photovoltaic storage box transformer itself, such as lighting load, ventilation and air conditioning equipment, communication equipment, monitoring equipment, etc. The photovoltaic panel is fixed by the pre-designed installation position of the photovoltaic storage box transformer, and the photovoltaic storage inverter and energy storage battery are integrated in the integrated photovoltaic storage control cabinet. The photovoltaic panel and the energy storage module are connected to the DC side of the photovoltaic storage inverter through a DC converter, respectively, so that the characteristics of the DC power in the photovoltaic storage inverter meet the requirements of the photovoltaic storage inverter. The function of the DC converter is to keep the output current of the photovoltaic panel or energy storage module able to meet the setting of the reference value, so that the output forms of the load current, photovoltaic current, and energy storage current are consistent, and dynamic compensation is achieved. The specific conversion process is a mature existing technology and will not be repeated here. The AC side of the photovoltaic storage inverter is connected to the transformer module through a main grid inverter to achieve mutual conversion between AC and DC between the grid side and the DC side of the photovoltaic storage inverter.

[0028] Photovoltaic panels, energy storage batteries, and loads are connected by a DC bus, which has the following advantages: it can eliminate the reactive power problem in AC; the transmission cables in the DC system can use a smaller cross-sectional area because the effective value of the DC current is smaller for the same power transmission; modern electronic equipment (such as computers, LED lighting, electric vehicles, etc.) usually use DC power supplies, and DC power distribution can reduce the intermediate links in power conversion and improve the overall efficiency of the system; the DC system can provide a more stable voltage output, avoiding quality problems caused by frequency and voltage fluctuations in the AC system; without the need for frequency synchronization, photovoltaic power generation can be directly coupled with the energy of the battery and the load.

[0029] The photovoltaic output current (photovoltaic current) can be measured through the photovoltaic storage inverter, and the photovoltaic current can be transmitted to the energy storage module through the signal transmission line. The photovoltaic storage inverter includes a photovoltaic inverter and an energy storage inverter. The photovoltaic panels and energy storage batteries are connected to different ports of the photovoltaic storage inverter through their own DC converters to achieve the connection between the photovoltaic panels and the photovoltaic storage inverter, and the connection between the energy storage module and the energy storage inverter. The function of the photovoltaic inverter is to measure the photovoltaic output current. The photovoltaic inverter and the energy storage inverter are connected through a signal transmission line to transmit the photovoltaic output current to the energy storage inverter. The energy storage inverter adjusts the working state and current size of the energy storage module according to the photovoltaic current.

[0030] The load rated current is the total load current inside the box-type transformer that maintains the basic operation of the photovoltaic storage box-type transformer system, including but not limited to: lighting load, ventilation and air conditioning equipment, communication equipment, monitoring equipment, etc. The load rated current is the sum of the rated currents of each load inside the box-type transformer, which is a fixed value. However, the real-time load current will change due to different external environments or the working state of the photovoltaic storage box-type transformer system. For example, when the ambient temperature is too high, the ventilation and air conditioning equipment needs to increase the power to quickly reduce the internal temperature of the box-type transformer. This is just an example, but it is not limited to this.

[0031] The maximum energy storage current is related to the state of charge of the energy storage module. Different states of charge have different maximum charge and discharge currents of the energy storage module. The maximum energy storage current needs to be determined in combination with the current state of charge of the energy storage module. The normal state of charge range can be 10% to 90% of the total state of charge of the energy storage module, which is only an example, but not limited to this.

[0032] Step S102, determining the power supply strategy of the photovoltaic box-to-box transformer system according to the relationship between the photovoltaic current, the load rated current, the maximum energy storage current, and the relationship between the energy storage charge state and the normal charge state range.

[0033] Specifically, based on the relationship between photovoltaic current, load rated current, and maximum energy storage current, it can be determined whether the power of photovoltaic power generation and energy storage modules can meet the operating requirements of the load, and then determine the power supply strategy of the photovoltaic storage box transformer system. The relationship between the energy storage charge state and the normal charge state range can determine whether the energy storage module can be charged and discharged normally, which can be used as an auxiliary judgment for the power supply strategy of the photovoltaic storage box transformer system to avoid overcharging or over-discharging of the energy storage module and extend the service life of the energy storage module.

[0034] The sustainable power supply method for the photovoltaic power storage box transformer system provided in this embodiment monitors the current parameters on the DC side of the photovoltaic power storage box transformer system, and dynamically adjusts the power supply strategy of the photovoltaic power storage box transformer system according to the relationship between the current parameters, so as to ensure the optimal distribution of energy flow, minimize the phenomenon of photovoltaic power generation abandonment, improve energy utilization efficiency, and realize efficient transmission, distribution and sustainable power supply of electricity, so as to ensure the stable operation of the system.

[0035] In some optional embodiments, the method further comprises: Step a1, obtaining the energy storage current, load current and the collection point current on the DC side of the photovoltaic energy storage inverter.

[0036] Specifically, the energy storage current is the real-time current of the charging and discharging process between the energy storage module and the photovoltaic storage inverter. The state of charge of the energy storage battery, the load current, and the photovoltaic current will all affect the size of the energy storage current. For example, when the photovoltaic panel and the energy storage module jointly power the load, the photovoltaic current remains unchanged, and the state of charge of the energy storage battery remains unchanged. At this time, if the load current increases, the energy storage current needs to increase to ensure the load demand. This is only an example, but not limited to this. The photovoltaic panel, the energy storage module, and the basic load are respectively connected to the DC side of the photovoltaic storage inverter through the DC bus. After the photovoltaic current, the load current, and the energy storage current are collected in the photovoltaic storage inverter, they are collected at the collection point on the DC side of the photovoltaic storage inverter and enter the AC side. The current sensor can be used for real-time monitoring to obtain the energy storage current, the load current, and the collection point current on the DC side of the photovoltaic storage inverter.

[0037] Step a2, judging whether a DC fault occurs in the photovoltaic storage box-type transformer system according to the relationship between the collection point current on the DC side of the photovoltaic storage inverter and the photovoltaic current, load current and energy storage current.

[0038] Specifically, in normal operation, the relationship between the currents on the DC side of the photovoltaic storage inverter of the photovoltaic storage box transformer system is as follows: (1) Among them, I PCC is the current at the collection point on the DC side of the photovoltaic storage inverter, I load is the load current, I PV is the photovoltaic current, I BAT is the energy storage current.

[0039] The photovoltaic current of the photovoltaic output will be directly reflected in the current at the collection point. The output current of the energy storage module is used as compensation for the fluctuation of the photovoltaic output current to power the load, ensuring that the photovoltaic power is used to power the load first. When the photovoltaic power generation is insufficient (for example: insufficient sunlight and at night), the energy storage battery serves as a backup power source to power the load. When the photovoltaic power generation is sufficient or even excessive, the excess power is used to charge the energy storage battery or transmitted to the power grid.

[0040] Step a3: If a DC fault occurs, the power supply lines from the photovoltaic panels and energy storage modules in the photovoltaic-storage box-to-transformer system to the load are cut off.

[0041] Specifically, the photovoltaic DC converter and energy storage DC converter can be turned off to disconnect the power supply line of the photovoltaic power supply equipment (including photovoltaic panels and energy storage modules) to the load, so as to achieve the purpose of controlling the photovoltaic power supply system to stop photovoltaic energy supply. This is only an example, but not limited to this. Figure 3The figure shows the energy control flow chart of the photovoltaic box-to-box transformer system. Before performing energy control, it is necessary to determine whether a DC fault occurs in the photovoltaic box-to-box transformer system based on the relationship between the collection point current on the DC side of the transformer and the photovoltaic current, load current, and energy storage current, so as to ensure the stable operation of the photovoltaic box-to-box transformer system.

[0042] In some optional implementations, judging whether a DC fault occurs based on the relationship between the collection point current on the DC side of the photovoltaic energy storage inverter and the photovoltaic current, the load current, and the energy storage current includes: Step a21, if the collection point current on the DC side of the photovoltaic storage inverter is equal to the sum of the photovoltaic current, the load current, and the energy storage current, then there is no DC fault in the photovoltaic storage box transformer system.

[0043] Step a22, if the collection point current on the DC side of the photovoltaic storage inverter is not equal to the sum of the photovoltaic current, the load current, and the energy storage current, a DC fault occurs in the photovoltaic storage box transformer system.

[0044] Specifically, under normal circumstances, the relationship between the collection point current on the DC side of the photovoltaic storage inverter and the photovoltaic current, load current, and energy storage current satisfies the above formula (1). If other situations occur, it means that a DC fault has occurred in the photovoltaic storage box transformer system. Using current amplitude for protection is an efficient technical means. By monitoring and analyzing the changes in current amplitude, the system can quickly identify abnormal conditions or potential faults. Related protection means often use the current change rate to judge protection, which has poor reliability. Compared with traditional fault identification methods, the method in this embodiment does not need to independently set a specific protection threshold for each device or each fault type, which simplifies the configuration and maintenance of the system, reduces the risk of human setting errors, and improves the response speed and accuracy of the system.

[0045] The sustainable power supply method for the photovoltaic storage box-to-transformer system provided in this embodiment determines the operating status of the photovoltaic storage box-to-transformer system by real-time monitoring and comparison of the sum of the photovoltaic current, load current, and energy storage current with the current of the DC side collection point of the photovoltaic storage inverter, and identifies possible faults in the system, so as to take corresponding maintenance and repair measures in time to avoid energy loss caused by the expansion or long-term existence of the fault, reduce unnecessary energy consumption of the energy storage battery under abnormal conditions, maximize the overall energy efficiency of the system, and realize efficient and stable operation of the photovoltaic storage system.

[0046] In this embodiment, a sustainable power supply method for a tank-to-tank transformer system is provided, which can be used in the above-mentioned computer system. Figure 4 is a flow chart of a sustainable power supply method for a storage tank transformer system according to an embodiment of the present invention. Figure 4 As shown, the process includes the following steps: Step S201, obtain the photovoltaic current, load rated current, energy storage maximum current, energy storage charge state, and determine the relationship between the photovoltaic current, load rated current, and energy storage maximum current, and the relationship between the energy storage charge state and the normal charge state range. The energy storage maximum current is the maximum charge and discharge current of the energy storage module under the current charge state. For details, please refer to Figure 2 Step S101 of the illustrated embodiment will not be described in detail here.

[0047] Step S202, determining the power supply strategy of the photovoltaic box-to-box transformer system according to the relationship between the photovoltaic current, the load rated current, the maximum energy storage current, and the relationship between the energy storage charge state and the normal charge state range.

[0048] Specifically, the above step S202 includes: Step S2021, if the photovoltaic current is greater than the rated current of the load, the electric energy generated by the photovoltaic panel is used to power the photovoltaic storage box transformer system, and the part of the photovoltaic current that is greater than the rated current of the load is used to charge the energy storage module.

[0049] Specifically, this embodiment adjusts the output power of the energy storage module according to the relationship between the photovoltaic current generated by photovoltaic power generation and the rated current of the load, so as to achieve sustainable power supply to the load.

[0050] like Figure 3 As shown, the photovoltaic solar energy storage inverter measures and determines the current of the photovoltaic module as the photovoltaic current, and compares it with the rated current of the load. If the photovoltaic current output by the photovoltaic power generation is greater than the rated current of the load, the photovoltaic power generation supplies power to the load and the excess electric energy is used to charge the energy storage module.

[0051] Step S2022: If the charge state of the energy storage module reaches the upper limit of the normal charge state range, the portion of the photovoltaic current that is greater than the rated current of the load enters the grid through the photovoltaic storage inverter and transformer module.

[0052] Specifically, since the state of charge of the energy storage module is limited and cannot be charged indefinitely, Figure 3 As shown, when the charge state of the energy storage module reaches the upper limit of the normal charge state range, the energy storage module is stopped from being charged, and the excess electric energy enters the grid side through the photovoltaic storage inverter to supply power to the electrical equipment on the grid side.

[0053] The sustainable power supply method for the photovoltaic storage box transformer system provided in this embodiment directly uses photovoltaic power generation to power the load of the photovoltaic storage box transformer system when there is too much photovoltaic power generation, thereby improving energy utilization. The excess electricity from photovoltaic power generation is used to charge the energy storage module or enter the power grid, thereby maximizing the use of photovoltaic power generation, reducing the phenomenon of photovoltaic power generation abandonment, and realizing efficient transmission and distribution of electricity.

[0054] Step S2023, if the photovoltaic current is less than the rated current of the load, and the maximum energy storage current is greater than the difference between the photovoltaic current and the rated current of the load, the electric energy generated by the photovoltaic panel and the electric energy stored in the energy storage module are used to jointly power the photovoltaic storage box transformer system.

[0055] Specifically, if the photovoltaic current is less than the rated current of the load, it means that the electricity generated by photovoltaic power generation cannot meet the load demand of the photovoltaic box-to-storage transformer system, and the energy of the energy storage module is needed to compensate. At this time, the maximum energy storage current is determined according to the state of charge of the energy storage module. According to the positive correlation between the state of charge of the energy storage battery and the terminal voltage, the smaller the state of charge, the smaller the terminal voltage, and the smaller the current when the load remains unchanged. Therefore, the maximum energy storage current can be determined according to the state of charge of the energy storage module. If the maximum energy storage current is greater than the difference between the photovoltaic current and the rated current of the load, it means that the energy storage module can completely compensate for the insufficient photovoltaic power generation and supply power to the load. The electricity generated by the photovoltaic panel and the electricity stored in the energy storage module are used to jointly supply power to the photovoltaic box-to-storage transformer system. After the DC converter of the energy storage module, the difference between the rated current of the load and the photovoltaic current and the maximum energy storage current is calculated ( ,in, Indicates the load rated current, represents the photovoltaic current, Represents the maximum energy storage current), the difference is passed through the proportional integral controller (PI) to generate a phase shift phase angle, and a switch control signal is generated through phase shift modulation, which is transmitted to the photovoltaic storage inverter switch to drive the control of the energy storage current output by the battery group, so that the energy storage current meets , ensuring that the photovoltaic power generation and energy storage modules meet the power supply needs of the load and do not consume the power in the grid. When the light is insufficient, the energy storage module is automatically used for compensation to ensure continuous and stable power supply to the load of the photovoltaic storage box transformer system.

[0056] like Figure 5 As shown in the figure, it is a schematic diagram of the control signal of the energy storage module charging and discharging. In addition to the above-mentioned energy storage battery and photovoltaic panel jointly powering the load In addition, photovoltaic current Greater than the load rated current When the energy storage module is charged, the energy storage module is controlled to charge; the state of charge SOC of the energy storage module exceeds the normal state of charge range SOC threslt When the charging and discharging stops, if the current at the collection point on the DC side of the photovoltaic storage inverter is Not equal to photovoltaic current , Load current , energy storage current If the sum of the two is greater, a DC fault occurs in the photovoltaic storage box transformer system, and the DC converter of the control storage module is shut down.

[0057] The sustainable power supply method for the photovoltaic storage box-type transformer system provided in this embodiment realizes efficient energy flow between photovoltaic power generation and energy storage modules when photovoltaic power generation is insufficient to support the basic operation of the photovoltaic storage box-type transformer system, gives priority to calling the electric energy of the energy storage modules, reduces dependence on the power grid, improves the independence and reliability of the secondary circuit of the box-type transformer system, ensures that photovoltaic power generation is fully utilized, and realizes efficient and stable operation of the photovoltaic storage box-type transformer system.

[0058] Step S2024, if the photovoltaic current is less than the rated current of the load, the maximum energy storage current is not greater than the difference between the photovoltaic current and the rated current of the load, and the energy storage charge state is within the normal charge state range, then the power of the grid, the power of the energy storage module, and the power generated by the photovoltaic panel are used to power the photovoltaic storage box transformer system.

[0059] Specifically, Figure 3 As shown, if the photovoltaic current is less than the rated current of the load, and the maximum energy storage current is not greater than the difference between the photovoltaic current and the rated current of the load, it means that the energy storage module and photovoltaic power generation cannot meet the load demand. It is necessary to further determine whether the energy storage module can discharge normally, that is, to determine whether the energy storage charge state is within the normal charge state range. If it is, the power grid and energy storage module are mainly used to power the photovoltaic storage box transformer system. Although the power generated by the photovoltaic panel is small, it will also be used to power the photovoltaic storage box transformer system. Adjust the charge and discharge current according to the charge state of the energy storage battery and the load demand, so that the energy storage battery is always in the best state, reducing the cost of maintaining and replacing the energy storage battery.

[0060] The sustainable power supply method for the photovoltaic storage box transformer system provided in this embodiment mainly utilizes the electric energy of the power grid and the energy storage module to power the photovoltaic storage box transformer system when the photovoltaic power generation is too small and the current that can be provided by the energy storage module is also very small, and the electric energy in the photovoltaic power generation and the energy storage module cannot meet the load demand, so as to achieve sustainable power supply and maintain stable operation of the photovoltaic storage box transformer system.

[0061] Step S2025: If the photovoltaic current is less than the rated current of the load and the energy storage charge state is less than the lower limit of the normal charge state range, the electric energy in the grid is used to power the photovoltaic storage box transformer system.

[0062] Specifically, Figure 3 As shown, if the photovoltaic current is less than the rated current of the load, and the energy storage charge state is less than the lower limit of the normal charge state range, it means that the energy storage module cannot discharge, and the electric energy in the grid is directly used to power the load of the photovoltaic storage box transformer system.

[0063] The sustainable power supply method for the photovoltaic storage box transformer system provided in this embodiment, when the photovoltaic power generation is too small, and the current that can be provided by the energy storage module is also very small, and the charge state of the energy storage module is too low, the power grid is fully utilized to supply power to the load of the photovoltaic storage box transformer system, to compensate for the influence of light fluctuations, to ensure a stable power supply, to avoid safety hazards and economic losses caused by power outages, and to avoid overcharging and over-discharging by accurately managing the charging and discharging process of the energy storage module, thereby extending the service life of the energy storage module.

[0064] In a specific embodiment, Figure 6 As shown, it is a schematic diagram of the current changes in the photovoltaic storage box transformer system in the simulation. The voltage of the common connection point (collection point) is 750V DC, the rated output power of photovoltaic is 25KW, the corresponding photovoltaic current of photovoltaic output is 33.3A, the rated power of load is 20KW, and the corresponding load current is 26.7A.

[0065] (1) During the period of 0.1s to 0.2s, since the power generated by the photovoltaic panel is greater than the load consumption, the excess power of 5KW, corresponding to 6.67A, is stored in the battery or input into the grid. Figure 6 As shown, the battery current is 0, which is equivalent to the battery being fully charged, and the PCC current is negative, indicating that the excess current generated by the photovoltaic panel flows to the grid.

[0066] (2) At 0.2s, the photovoltaic output weakened to 11.25KW, and the corresponding photovoltaic current decreased to 15A. The photovoltaic current was less than the rated current of the load. The energy storage module (battery) used the sustainable power supply method of the photovoltaic storage box transformer system provided by the present invention to determine that the energy storage output power was 8.75KW, and the corresponding energy storage current became 11.67A. The photovoltaic panel and the battery jointly powered the load, and the power grid did not provide additional power to the load.

[0067] (3) At 0.3s, the power generated by the photovoltaic panel recovers to the maximum of 25KW, corresponding to the photovoltaic current recovery of 33.3A. The photovoltaic current is greater than the rated current of the load, and the output current of the battery is reduced to 0. The load consumption is completely provided by photovoltaic power generation, and no power from the grid is absorbed.

[0068] In this embodiment, a sustainable power supply device for a photovoltaic storage box transformer system is also provided, which is used to implement the above-mentioned embodiments and preferred implementation modes, and will not be repeated hereafter. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0069] This embodiment provides a sustainable power supply device for a photovoltaic storage box transformer system, the photovoltaic storage box transformer system includes: a transformer module, a photovoltaic panel, a photovoltaic storage inverter, an energy storage module, a basic load, and a DC bus. The photovoltaic panel, the energy storage module, and the basic load are respectively connected to the DC side of the photovoltaic storage inverter through the DC bus, and the AC side of the photovoltaic storage inverter is connected to the power grid through the transformer module. Figure 7 As shown, including: The data acquisition module 701 is used to obtain the photovoltaic current, the rated load current, the maximum energy storage current, and the energy storage charge state, and determine the relationship between the photovoltaic current, the rated load current, and the maximum energy storage current, and the relationship between the energy storage charge state and the normal charge state range. The maximum energy storage current is the maximum charge and discharge current of the energy storage module under the current charge state.

[0070] The power supply strategy determination module 702 is used to determine the power supply strategy of the photovoltaic storage box transformer system according to the relationship between the photovoltaic current, the load rated current, the maximum energy storage current, and the relationship between the energy storage charge state and the normal charge state range.

[0071] In some optional implementations, the power supply strategy determination module 702 includes: The energy storage charging unit is used to use the electricity generated by the photovoltaic panels to power the photovoltaic box-to-box system if the photovoltaic current is greater than the rated current of the load. The part of the photovoltaic current that is greater than the rated current of the load is used to charge the energy storage module.

[0072] The grid access unit is used to allow the photovoltaic current that is greater than the rated current of the load to enter the grid through the photovoltaic storage inverter and transformer module if the charge state of the energy storage module reaches the upper limit of the normal charge state range.

[0073] The photovoltaic and energy storage collaborative power supply unit is used to use the electric energy generated by the photovoltaic panels and the electric energy stored in the energy storage module to jointly power the photovoltaic storage box transformer system if the photovoltaic current is less than the rated current of the load and the maximum current of the energy storage is greater than the difference between the photovoltaic current and the rated current of the load.

[0074] The grid and energy storage collaborative power supply unit is used to use the power of the grid, the power of the energy storage module, and the power generated by the photovoltaic panel to power the photovoltaic storage box transformer system if the photovoltaic current is less than the rated current of the load, the maximum current of the energy storage is not greater than the difference between the photovoltaic current and the rated current of the load, and the energy storage charge state is within the normal charge state range.

[0075] The grid power supply unit is used to use the electric energy in the grid to power the photovoltaic storage box transformer system if the photovoltaic current is less than the rated current of the load and the energy storage charge state is less than the lower limit of the normal charge state range.

[0076] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0077] The sustainable power supply device of the photovoltaic storage box transformer system in this embodiment is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0078] The embodiment of the present invention also provides a computer device having the above Figure 7 The sustainable power supply device of the photovoltaic storage box transformer system shown.

[0079] See also Figure 8 , Figure 8 is a schematic diagram of the structure of a computer device provided by an optional embodiment of the present invention, such as Figure 8 As shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 8 A processor 10 is taken as an example.

[0080] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0081] The memory 20 stores instructions executable by at least one processor 10, so that the at least one processor 10 executes the method shown in the above embodiment.

[0082] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0083] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0084] The computer device further comprises a communication interface 30 for the computer device to communicate with other devices or a communication network.

[0085] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0086] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A sustainable power supply method for a photovoltaic storage box transformer system, the photovoltaic storage box transformer system comprising: Transformer module, photovoltaic panel, photovoltaic storage inverter, energy storage module, basic load, DC bus, photovoltaic panel, energy storage module, basic load are respectively connected to the DC side of the photovoltaic storage inverter through the DC bus, and the AC side of the photovoltaic storage inverter is connected to the power grid through the transformer module, characterized in that the method includes: Obtaining the photovoltaic current, the rated load current, the maximum energy storage current, and the energy storage charge state, and determining the relationship between the photovoltaic current, the rated load current, and the maximum energy storage current, and the relationship between the energy storage charge state and the normal charge state range, wherein the maximum energy storage current is the maximum charge and discharge current of the energy storage module under the current charge state; The power supply strategy of the photovoltaic-storage box-type transformer system is determined based on the relationship between the photovoltaic current, the load rated current, the maximum energy storage current, and the relationship between the energy storage charge state and the normal charge state range.

2. The method according to claim 1, characterized in that The method further comprises: Obtain energy storage current, load current and the collection point current on the DC side of the photovoltaic storage inverter; According to the relationship between the collection point current on the DC side of the photovoltaic storage inverter and the photovoltaic current, load current, and energy storage current, it is determined whether the photovoltaic storage box transformer system has a DC fault; If a DC fault occurs, the power supply line from the photovoltaic panel and the energy storage module to the load in the photovoltaic storage box transformer system is cut off.

3. The method according to claim 2, characterized in that Determine whether a DC fault occurs based on the relationship between the current at the collection point on the DC side of the photovoltaic energy storage inverter and the photovoltaic current, load current, and energy storage current, including: If the current at the collection point on the DC side of the photovoltaic storage inverter is equal to the sum of the photovoltaic current, load current, and energy storage current, then there is no DC fault in the photovoltaic storage box transformer system; If the collection point current on the DC side of the photovoltaic storage inverter is not equal to the sum of the photovoltaic current, load current, and energy storage current, a DC fault occurs in the photovoltaic storage box transformer system.

4. The method according to claim 1, characterized in that: The power supply strategy of the photovoltaic storage box transformer system is determined according to the relationship between the photovoltaic current, the load rated current, the maximum energy storage current, and the relationship between the energy storage charge state and the normal charge state range, including: If the photovoltaic current is greater than the rated current of the load, the electric energy generated by the photovoltaic panel is used to power the photovoltaic storage box transformer system, and the part of the photovoltaic current that is greater than the rated current of the load is used to charge the energy storage module; If the charge state of the energy storage module reaches the upper limit of the normal charge state range, the portion of the photovoltaic current that is greater than the rated current of the load enters the power grid through the photovoltaic storage inverter and transformer module.

5. The method according to claim 1, characterized in that The power supply strategy of the photovoltaic storage box transformer system is determined according to the relationship between the photovoltaic current, the load rated current, the maximum energy storage current, and the relationship between the energy storage charge state and the normal charge state range, including: If the photovoltaic current is less than the rated current of the load, and the maximum energy storage current is greater than the difference between the photovoltaic current and the rated current of the load, the electric energy generated by the photovoltaic panel and the electric energy stored in the energy storage module are used to power the photovoltaic storage box transformer system.

6. The method according to claim 1, characterized in that The power supply strategy of the photovoltaic storage box transformer system is determined according to the relationship between the photovoltaic current, the load rated current, the maximum energy storage current, and the relationship between the energy storage charge state and the normal charge state range, including: If the photovoltaic current is less than the rated current of the load, the maximum energy storage current is not greater than the difference between the photovoltaic current and the rated current of the load, and the energy storage charge state is within the normal charge state range, the power of the power grid, the power of the energy storage module, and the power generated by the photovoltaic panel are used to power the photovoltaic storage box transformer system.

7. The method according to claim 1, characterized in that The power supply strategy of the photovoltaic storage box transformer system is determined according to the relationship between the photovoltaic current, the load rated current, the maximum energy storage current, and the relationship between the energy storage charge state and the normal charge state range, including: If the photovoltaic current is less than the rated current of the load and the energy storage charge state is less than the lower limit of the normal charge state range, the electric energy in the power grid is used to power the photovoltaic storage box transformer system.

8. A sustainable power supply device for a photovoltaic storage box transformer system, the photovoltaic storage box transformer system comprising: Transformer module, photovoltaic panel, photovoltaic storage inverter, energy storage module, basic load, DC bus, photovoltaic panel, energy storage module, basic load are respectively connected to the DC side of the photovoltaic storage inverter through the DC bus, and the AC side of the photovoltaic storage inverter is connected to the power grid through the transformer module, characterized in that the device includes: A data acquisition module is used to obtain the photovoltaic current, the rated load current, the maximum energy storage current, and the energy storage charge state, and determine the relationship between the photovoltaic current, the rated load current, and the maximum energy storage current, and the relationship between the energy storage charge state and the normal charge state range, wherein the maximum energy storage current is the maximum charge and discharge current of the energy storage module under the current charge state; The power supply strategy determination module is used to determine the power supply strategy of the photovoltaic storage box transformer system based on the relationship between the photovoltaic current, the load rated current, the maximum energy storage current, and the relationship between the energy storage charge state and the normal charge state range.

9. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the method according to any one of claims 1 to 7 by executing the computer instructions.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the method according to any one of claims 1 to 7.

Images