Charging and discharging control methods, systems, devices, and media based on DC microgrids

Abstract

This invention discloses a charging and discharging control method, system, device, and medium based on a DC microgrid. The method includes: determining whether the DC microgrid is powered down; when the DC microgrid is powered down, providing emergency power to the load devices in the DC microgrid using the available stored electrical energy of an energy storage element; when the DC microgrid is not powered down, determining whether the load feedback power is greater than the load consumption power; when the load feedback power is greater than the load consumption power, recovering electrical energy through the energy storage element; when the load operating power is greater than or equal to the transformer's rated power, compensating for the transformer's rated power; when the load operating power is less than the transformer's rated power, charging the energy storage element during the AC grid's low-load period and discharging the energy storage element during the AC grid's high-load period. This invention improves the power supply efficiency of the DC microgrid, ensures the stability and reliability of the DC microgrid, and can be widely applied in the field of microgrid energy storage control technology.

Description

Technical Field

[0001] This invention relates to the field of microgrid energy storage control technology, and in particular to a charging and discharging control method, system, device and medium based on a DC microgrid. Background Technology

[0002] DC microgrids are microgrids composed of direct current (DC) and are an important component of future smart power distribution systems. They are of great significance for promoting energy conservation and emission reduction and achieving sustainable energy development. Compared to AC microgrids, DC microgrids can more efficiently and reliably accommodate distributed renewable energy generation systems such as wind and solar power, energy storage devices, electric vehicles, and other DC loads.

[0003] Existing charging and discharging control methods for energy storage components in DC microgrids do not consider issues such as emergency power supply, absorption of feedback power, and peak shaving and valley filling of electricity loads, which reduces the power supply efficiency of DC microgrids and affects their stability and reliability. Summary of the Invention

[0004] The purpose of this invention is to at least partially solve one of the technical problems existing in the prior art.

[0005] Therefore, one objective of this invention is to provide a charging and discharging control method based on a DC microgrid, which improves the power supply efficiency of the DC microgrid and ensures its stability and reliability.

[0006] Another objective of this invention is to provide a charging and discharging control system based on a DC microgrid.

[0007] To achieve the above-mentioned technical objectives, the technical solutions adopted in the embodiments of the present invention include:

[0008] In a first aspect, embodiments of the present invention provide a charging and discharging control method based on a DC microgrid, comprising the following steps:

[0009] Determine whether the DC microgrid is powered off; when the DC microgrid is powered off, provide emergency power to the load devices in the DC microgrid through the available stored electrical energy of the energy storage element.

[0010] When the DC microgrid is not powered off, it is determined whether the load feedback power is greater than the load consumption power. If the load feedback power is greater than the load consumption power, energy is recovered through the energy storage element.

[0011] When the load operating power is greater than or equal to the transformer's rated power, the transformer's rated power is compensated.

[0012] When the load operating power is less than the transformer's rated power, the energy storage element is charged during the off-peak hours of the AC power grid and discharged during the peak hours of the AC power grid.

[0013] Furthermore, in one embodiment of the present invention, the step of providing emergency power to the load devices in the DC microgrid through the available stored electrical energy of the energy storage element specifically includes:

[0014] Obtain the available stored electrical energy of the energy storage element;

[0015] The first total electrical energy required for the operation of the load device is determined based on the power of the load device and the preset first operating time.

[0016] When the available stored electrical energy is greater than or equal to the first total electrical energy, emergency power is supplied to the load device through the available stored electrical energy;

[0017] When the available stored power is less than the first total power, the operating priority of the load device is obtained, and several important loads are determined according to the operating priority, thereby determining the second total power required for the operation of the important loads;

[0018] When the available stored electrical energy is greater than or equal to the second total electrical energy, emergency power is supplied to the critical load through the available stored electrical energy;

[0019] If the available stored power is less than the second total power, return to the step of determining several important loads based on the running priority, until the available stored power is greater than or equal to the optimized second total power.

[0020] Furthermore, in one embodiment of the present invention, the step of recovering electrical energy through the energy storage element specifically includes:

[0021] When power utilization is prioritized, the load feedback power of the load device and the absorbable power of the energy storage element are obtained in the current time period, and it is determined whether the absorbable power is less than the load feedback power.

[0022] When the absorbable electrical energy is greater than or equal to the load feedback electrical energy, the energy storage element is charged through the load feedback electrical energy until the available stored electrical energy of the energy storage element reaches a preset first threshold.

[0023] When the absorbable energy is less than the load feedback energy, the discharge power and discharge duration of the energy storage element are determined, and the energy storage element is discharged according to the discharge power and the discharge duration. Then, after the discharge is completed, the absorbable energy of the energy storage element is updated until the updated absorbable energy is greater than or equal to the load feedback energy.

[0024] Furthermore, in one embodiment of the present invention, the step of recovering electrical energy through the energy storage element specifically includes:

[0025] When energy storage protection is prioritized, the load feedback energy of the load device and the absorbable energy of the energy storage element are obtained during the current period, and the first optimal charging power is calculated based on the absorbable energy.

[0026] Based on the first optimal charging power, the energy storage element is charged by the load feedback power until the available stored power of the energy storage element reaches a preset second threshold.

[0027] Furthermore, in one embodiment of the present invention, the step of compensating for the rated power of the transformer specifically includes:

[0028] The device operating power of the load equipment and the rated power of the transformer in the DC microgrid are obtained. When the device operating power is greater than or equal to the rated power of the transformer, the first discharge power of the energy storage element is calculated based on the device operating power and the rated power of the transformer.

[0029] The first discharge duration of the energy storage element is calculated based on the first discharge power and the available stored energy of the energy storage element, and the first operating duration preset by the load device is obtained.

[0030] When the first discharge duration is greater than or equal to the first operating duration, the energy storage element is controlled to discharge according to the first discharge power.

[0031] When the first discharge duration is less than the first operating duration, the operating priority of the load device is obtained, and several important loads are determined according to the operating priority. Then, the second discharge power of the energy storage element is calculated according to the important loads, and the second discharge duration of the energy storage element is determined.

[0032] When the second discharge duration is greater than or equal to the first operating duration, the energy storage element is discharged according to the second discharge power;

[0033] If the second discharge duration is less than the first running duration, return to the step of determining several important loads based on the running priority, until the optimized second discharge duration is greater than or equal to the first running duration.

[0034] Furthermore, in one embodiment of the present invention, the step of charging the energy storage element during off-peak hours of the AC power grid specifically includes:

[0035] Determine that the AC power grid is in a period of low electricity load, and obtain the rechargeable electrical energy of the energy storage element;

[0036] Calculate the second optimal charging power of the energy storage element based on the rechargeable electrical energy;

[0037] The energy storage element is charged according to the second optimal charging power until the available stored energy of the energy storage element reaches a preset third threshold.

[0038] Furthermore, in one embodiment of the present invention, the step of discharging the energy storage element during peak load periods of the AC power grid specifically includes:

[0039] Determine that the AC power grid is in a peak load period, and obtain the dischargeable electrical energy of the energy storage element;

[0040] The optimal discharge power of the energy storage element is calculated based on the dischargeable electrical energy.

[0041] The energy storage element is discharged according to the optimal discharge power until the available stored energy of the energy storage element reaches a preset fourth threshold.

[0042] Secondly, embodiments of the present invention provide a charging and discharging control system based on a DC microgrid, comprising:

[0043] An emergency power supply module is used to determine whether the DC microgrid is powered off. When the DC microgrid is powered off, it provides emergency power to the load devices in the DC microgrid through the available stored electrical energy of the energy storage element.

[0044] The energy recovery module is used to determine whether the load feedback power is greater than the load consumption power when the DC microgrid is not interrupted; if the load feedback power is greater than the load consumption power, energy is recovered through the energy storage element.

[0045] The power compensation module is used to compensate for the rated power of the transformer when the operating power of the load is greater than or equal to the rated power of the transformer.

[0046] The power time-shifting module is used to charge the energy storage element during off-peak hours of the AC power grid when the load operating power is less than the transformer's rated power, and to discharge the energy storage element during peak hours of the AC power grid.

[0047] Thirdly, embodiments of the present invention provide a charging and discharging control device based on a DC microgrid, comprising:

[0048] At least one processor;

[0049] At least one memory for storing at least one program;

[0050] When the at least one program is executed by the at least one processor, the at least one processor implements the above-described charging and discharging control method based on a DC microgrid.

[0051] Fourthly, embodiments of the present invention also provide a computer-readable storage medium storing a processor-executable program, which, when executed by a processor, is used to perform the above-described charging and discharging control method based on a DC microgrid.

[0052] The advantages and beneficial effects of the present invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention:

[0053] This invention applies a DC microgrid based on a DC bus to the charging and discharging control of energy storage components. Combined with the structure of the DC microgrid, it deploys related processes for emergency power supply, energy recovery, and energy time shifting. Emergency power supply for load equipment can be achieved without the need for a UPS uninterruptible power supply. At the same time, it can also absorb the electrical energy fed back by the load equipment and realize peak shaving and valley filling of the electrical load through energy storage components, thereby improving the power supply efficiency of the DC microgrid and ensuring its stability and reliability. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the embodiments of the present invention are described below. It should be understood that the drawings described below are only for the convenience of clearly describing some embodiments of the technical solutions of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 A flowchart illustrating the steps of a charging and discharging control method based on a DC microgrid, provided in an embodiment of the present invention;

[0056] Figure 2 A schematic diagram of the structure of a DC microgrid provided in an embodiment of the present invention;

[0057] Figure 3 A structural block diagram of a charging and discharging control system based on a DC microgrid provided in an embodiment of the present invention;

[0058] Figure 4 This is a structural block diagram of a charging and discharging control device based on a DC microgrid, provided as an embodiment of the present invention. Detailed Implementation

[0059] The embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. The step numbers in the following embodiments are set only for ease of explanation, and there is no limitation on the order between the steps. The execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0060] In the description of this invention, "multiple" means two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or the order of the indicated technical features. Furthermore, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art.

[0061] Reference Figure 1 This invention provides a charging and discharging control method based on a DC microgrid, specifically including the following steps:

[0062] S101. Determine whether the DC microgrid is powered off. When the DC microgrid is powered off, provide emergency power to the load devices in the DC microgrid through the available stored electrical energy of the energy storage element.

[0063] Specifically, the DC microgrid of this invention includes a DC bus and distributed power sources, load devices, energy storage elements, and controllers connected to the DC bus. The distributed power sources include distributed DC sources and distributed AC sources, and the load devices include AC loads and DC loads. In addition, the DC bus can also be interconnected with the AC bus of the AC power grid, and a transformer is installed on the AC bus.

[0064] like Figure 2 The diagram shows a schematic of a DC microgrid provided in an embodiment of the present invention. This DC microgrid is applied in a lithium battery manufacturing plant. The distributed DC source can be a solar photovoltaic array, the distributed AC source can be a wind turbine generator, the energy storage element can be an electrochemical battery pack, the AC load can be a motor set or servo motor in the lithium battery manufacturing plant, and the DC load can be the charging and discharging equipment in the lithium battery manufacturing plant. In this embodiment, the distributed DC source, DC load, and energy storage element are connected to the DC bus via DC / DC converters, and the distributed AC source, AC load, and AC bus are connected to the DC bus via AC / DC converters. Emergency power supply, energy recovery, and energy time-shift control strategies are all executed by the controller of the DC microgrid.

[0065] In this embodiment of the invention, the energy storage element reserves a portion of its power, enabling it to provide uninterrupted power supply to critical loads connected to the DC bus after a power outage in the public power grid, thus ensuring the continuity of the customer's critical business operations.

[0066] As a further optional implementation, the step of providing emergency power to load devices in a DC microgrid using the available stored electrical energy of energy storage elements specifically includes:

[0067] A1. Obtain the available stored electrical energy from the energy storage element;

[0068] A2. Determine the first total electrical energy required for the operation of the load equipment based on the power of the load equipment and the preset first operating time;

[0069] A3. When the available stored electrical energy is greater than or equal to the first total electrical energy, emergency power supply is provided to the load equipment through the available stored electrical energy.

[0070] A4. When the available stored power is less than the first total power, obtain the operating priority of the load equipment, determine several important loads based on the operating priority, and then determine the second total power required for the operation of the important loads.

[0071] A5. When the available stored electrical energy is greater than or equal to the second total electrical energy, emergency power supply can be provided to critical loads using the available stored electrical energy.

[0072] A6. When the available stored power is less than the second total power, return to the step of determining several important loads based on the running priority until the available stored power is greater than or equal to the optimized second total power.

[0073] Specifically, the emergency triggering process of this invention aims to ensure the normal operation of critical load equipment during power outages. The first operating time is a pre-set operating time for the load equipment. The first total power is calculated based on the first operating time and the operating power of all load equipment. If the available stored power is less than the first total power, it means the stored power cannot support the operation of all load equipment. Therefore, some non-critical load equipment needs to be shut down according to the load equipment priority to adjust the load power. The second total power is the power required for the operation of critical loads, recalculated after optimization and adjustment of the load equipment. When the available stored power is greater than or equal to the second total power, it means the stored power is sufficient to support the operation of critical loads. At this time, emergency power can be supplied to critical loads using the available stored power. Furthermore, if the available stored power is still less than the second total power, the priority of the load equipment needs further optimization to redetermine the critical loads that need to continue operating. The priority of the load equipment is pre-set by the customer according to production needs.

[0074] S102. When the DC microgrid is not powered off, determine whether the load feedback power is greater than the load consumption power. If the load feedback power is greater than the load consumption power, recover electrical energy through energy storage elements.

[0075] Specifically, in a DC microgrid, some load devices release electrical energy when discharging, and some load devices consume electrical energy when charging. When the electrical energy released per unit time is greater than the electrical energy consumed per unit time, this excess electrical energy needs to be recovered and utilized, such as by storing it through energy storage elements or feeding it back to the AC bus.

[0076] The energy storage element in this embodiment of the invention reserves a portion of its capacity space, which can provide the ability to absorb the fed-back power when the power fed back by the load is greater than the power consumed by other loads, thereby enabling the effective utilization of the power fed back by the load device.

[0077] like Figure 2 As shown in the embodiment of the invention, the AC / DC converter between the DC bus and the AC bus can be a unidirectional AC / DC converter or a bidirectional AC / DC converter. When using a unidirectional AC / DC converter, the feedback energy cannot flow back into the grid. When using a bidirectional AC / DC converter, the feedback energy can flow back into the grid. Therefore, if a unidirectional AC / DC converter is used, only a scheme that fully absorbs the energy can be considered. Its main purpose is to absorb the energy feedback that may occur in the next stage. The main means of absorption is to charge the energy storage element when the load equipment cannot consume this part of the energy, thereby achieving the purpose of utilizing the energy fed back by the equipment. If a bidirectional AC / DC converter is used, the priority of energy storage protection needs to be considered. That is, when absorbing the feedback energy, the charging protection of the energy storage element needs to be considered. In addition, when using a unidirectional AC / DC converter or a bidirectional AC / DC converter, if the energy storage element cannot fully absorb the energy, it is necessary to discharge the energy storage element in advance to refresh the absorbable energy of the energy storage element, under the premise of prioritizing energy utilization. During this process, the power supply of the AC grid will be automatically adjusted, and there is no need to disconnect the AC grid. The AC grid and the energy storage element jointly supply power to the load equipment of the DC microgrid.

[0078] As an optional implementation method, the step of recovering electrical energy through energy storage elements specifically includes:

[0079] B1. When prioritizing power utilization, obtain the load feedback power of the load equipment and the absorbable power of the energy storage element in the current time period, and determine whether the absorbable power is less than the load feedback power.

[0080] B2. When the absorbable electrical energy is greater than or equal to the load feedback electrical energy, the energy storage element is charged through the load feedback electrical energy until the available stored electrical energy of the energy storage element reaches the preset first threshold.

[0081] B3. When the absorbable energy is less than the load feedback energy, determine the discharge power and discharge duration of the energy storage element, discharge the energy storage element according to the discharge power and discharge duration, and then update the absorbable energy of the energy storage element after the discharge is completed, until the updated absorbable energy is greater than or equal to the load feedback energy.

[0082] Specifically, when prioritizing energy utilization, there is no need to consider the lifespan of energy storage components; the battery can be repeatedly charged and discharged to maximize energy utilization.

[0083] As another optional implementation, the step of recovering electrical energy through energy storage elements specifically includes:

[0084] B4. When energy storage protection is prioritized, obtain the load feedback energy of the load device and the absorbable energy of the energy storage element in the current time period, and calculate the first optimal charging power based on the absorbable energy.

[0085] B5. Based on the first optimal charging power, the energy storage element is charged by the load feedback power until the available stored power of the energy storage element reaches the preset second threshold.

[0086] Specifically, when energy storage protection is prioritized, it is necessary to control the number of charge and discharge cycles and the charging power of the energy storage components to maximize their lifespan.

[0087] It is understandable that the first threshold is a pre-set upper limit of the energy storage element that can store energy under the condition of prioritizing energy utilization, and the second threshold is a pre-set upper limit of the energy storage element that can store energy under the condition of prioritizing energy storage protection. The first threshold and the second threshold can be set according to the actual situation.

[0088] S103. When the load operating power is greater than or equal to the transformer's rated power, the transformer's rated power shall be compensated.

[0089] In this embodiment of the invention, there are two cases for the charging and discharging control of time-shifted electrical energy: one is based on the aforementioned time-of-use pricing, and the other is based on the upper limit of transformer capacity. The upper limit of transformer capacity refers to the operating equipment reaching the maximum electrical energy provided by the transformer; exceeding this limit would lead to transformer failure. Therefore, energy storage batteries are needed to provide energy to share the load.

[0090] As a further optional implementation, the step of compensating for the rated power of the transformer specifically includes:

[0091] The device operating power of the load equipment and the rated power of the transformer in the DC microgrid are obtained. When the device operating power is greater than or equal to the rated power of the transformer, the first discharge power of the energy storage element is calculated based on the device operating power and the rated power of the transformer.

[0092] The first discharge duration of the energy storage element is calculated based on the first discharge power and the available stored electrical energy of the energy storage element, and the first operating duration preset by the load device is obtained.

[0093] When the first discharge duration is greater than or equal to the first operating duration, the energy storage element is controlled to discharge according to the first discharge power.

[0094] When the first discharge duration is less than the first operating duration, the operating priority of the load device is obtained, and several important loads are determined according to the operating priority. Then, the second discharge power of the energy storage element is calculated according to the important loads, and the second discharge duration of the energy storage element is determined.

[0095] When the second discharge duration is greater than or equal to the first operating duration, the energy storage element is discharged according to the second discharge power;

[0096] If the second discharge duration is less than the first running duration, return to the step of determining several important loads based on the running priority, until the optimized second discharge duration is greater than or equal to the first running duration.

[0097] Specifically, in this embodiment of the invention, when the operating power of the device is greater than or equal to the rated power of the transformer, it indicates that the electrical energy required by the operating load device has exceeded or is about to exceed the maximum electrical energy provided by the transformer. In order to avoid transformer failure, the load is shared by discharging the energy storage element, and the energy storage element can be charged during subsequent low-load periods, thereby realizing time shift of electrical energy.

[0098] S104. When the load operating power is less than the transformer's rated power, the energy storage element is charged during the off-peak hours of the AC power grid and discharged during the peak hours of the AC power grid.

[0099] Specifically, time shifting of electricity is a method of peak shaving and valley filling of electricity load through energy storage. This means charging the battery during periods of low electricity load and releasing the stored electricity during periods of high electricity load.

[0100] Understandably, the power sector divides the 24 hours of the day into peak, off-peak, and low-peak periods, and sets different electricity prices for each period—this is time-of-use pricing. Electricity prices are higher during peak hours and lower during off-peak hours. This time-shifting of energy consumption can reduce electricity costs.

[0101] In addition, the power supply department implements a two-part electricity pricing system for large industrial enterprises: the electricity price is based on the actual amount of electricity traded, while the capacity price depends primarily on the user's peak power consumption. Capacity cost management refers to reducing capacity costs by lowering the peak power consumption of the public power grid without affecting normal production. Users can utilize energy storage systems to store energy during off-peak hours and discharge the batteries to the load during peak hours, thereby reducing the overall grid load and achieving the goal of reducing capacity costs. Reducing the peak capacity demand of transformers can reduce the initial investment in transformers and alleviate the need for capacity expansion when electricity demand increases.

[0102] New energy sources, primarily wind and solar power, have unstable power outputs, characterized by large fluctuations and randomness. During peak periods of distributed generation, the surplus energy that the electricity load cannot consume can be stored in batteries and released to supply the electricity load during off-peak periods.

[0103] As a further optional implementation, the step of charging the energy storage element during off-peak hours of the AC power grid specifically includes:

[0104] D1. Determine that the AC power grid is in a period of low electricity load and obtain the rechargeable electrical energy of the energy storage element;

[0105] D2. Calculate the second optimal charging power of the energy storage element based on the rechargeable electrical energy;

[0106] D3. Charge the energy storage element according to the second optimal charging power until the available stored energy of the energy storage element reaches the preset third threshold.

[0107] As a further optional implementation, the step of discharging the energy storage element during peak load periods of the AC power grid specifically includes:

[0108] D4. Determine that the AC power grid is in a peak load period and obtain the dischargeable electrical energy of the energy storage element;

[0109] D5. Calculate the optimal discharge power of the energy storage element based on the dischargeable electrical energy;

[0110] D6. Discharge the energy storage element according to the optimal discharge power until the available stored energy of the energy storage element reaches the preset fourth threshold.

[0111] Specifically, the third threshold is a pre-set upper limit threshold for the energy storage element to store electrical energy. When this threshold is reached, charging stops to prevent overcharging. The fourth threshold is a pre-set lower limit threshold for the energy storage element to store electrical energy. When this threshold is reached, discharging stops to prevent over-discharging.

[0112] The method flow of the embodiments of the present invention has been described above. It is understood that the embodiments of the present invention apply a DC microgrid based on a DC bus to the charging and discharging control of energy storage components. Combined with the structure of the DC microgrid, relevant processes for emergency power supply, energy recovery, and energy time shifting are deployed. Emergency power supply to load devices can be achieved without a UPS uninterruptible power supply. Simultaneously, the energy fed back from the load devices can be absorbed, and the energy storage components achieve peak shaving and valley filling of the electrical load, thereby improving the power supply efficiency of the DC microgrid and ensuring its stability and reliability.

[0113] Reference Figure 3 This invention provides a charging and discharging control system based on a DC microgrid, comprising:

[0114] The emergency power supply module is used to determine whether the DC microgrid is out of power. When the DC microgrid is out of power, it provides emergency power to the load devices in the DC microgrid through the available stored electrical energy of the energy storage element.

[0115] The energy recovery module is used to determine whether the load feedback power is greater than the load consumption power when the DC microgrid is not interrupted. If the load feedback power is greater than the load consumption power, energy is recovered through energy storage elements.

[0116] The power compensation module is used to compensate for the rated power of the transformer when the operating power of the load is greater than or equal to the rated power of the transformer.

[0117] The power time-shifting module is used to charge the energy storage element during off-peak hours of the AC power grid and discharge the energy storage element during peak hours of the AC power grid when the load operating power is less than the transformer's rated power.

[0118] The content of the above method embodiments is applicable to this system embodiment. The specific functions implemented in this system embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0119] Reference Figure 4 This invention provides a charging and discharging control device based on a DC microgrid, comprising:

[0120] At least one processor;

[0121] At least one memory for storing at least one program;

[0122] When the above-mentioned at least one program is executed by the above-mentioned at least one processor, the above-mentioned at least one processor implements the above-mentioned charging and discharging control method based on DC microgrid.

[0123] The content of the above method embodiments is applicable to the device embodiments. The specific functions implemented by the device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0124] This invention also provides a computer-readable storage medium storing a processor-executable program that, when executed by a processor, performs the aforementioned charging and discharging control method based on a DC microgrid.

[0125] This invention provides a computer-readable storage medium that can execute a charging and discharging control method based on a DC microgrid provided in the method embodiments of this invention. It can execute any combination of the implementation steps of the method embodiments and has the corresponding functions and beneficial effects of the method.

[0126] This invention also discloses a computer program product or computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device can read the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, causing the computer device to perform... Figure 1 The method shown.

[0127] In some alternative embodiments, the functions / operations mentioned in the block diagrams may not occur in the order shown in the operation diagrams. For example, depending on the functions / operations involved, two consecutively shown blocks may actually be executed substantially simultaneously, or the aforementioned blocks may sometimes be executed in reverse order. Furthermore, the embodiments presented and described in the flowcharts of this invention are provided by way of example to provide a more comprehensive understanding of the technology. The disclosed methods are not limited to the operations and logic flows presented herein. Alternative embodiments are contemplated in which the order of various operations is changed and sub-operations described as part of a larger operation are executed independently.

[0128] Furthermore, although the invention has been described in the context of functional modules, it should be understood that, unless otherwise stated, one or more of the aforementioned functions and / or features may be integrated into a single physical device and / or software module, or one or more functions and / or features may be implemented in a separate physical device or software module. It is also understood that a detailed discussion of the actual implementation of each module is unnecessary for understanding the invention. Rather, given the properties, functions, and internal relationships of the various functional modules in the apparatus disclosed herein, the actual implementation of the module will be understood within the scope of conventional skill of an engineer. Therefore, those skilled in the art can implement the invention as set forth in the claims using ordinary techniques without excessive experimentation. It is also understood that the specific concepts disclosed are merely illustrative and not intended to limit the scope of the invention, which is determined by the full scope of the appended claims and their equivalents.

[0129] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0130] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0131] More specific examples of computer-readable media (a non-exhaustive list) include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which the aforementioned program can be printed, because the aforementioned program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or, if necessary, processing in other suitable ways, and then stored in computer memory.

[0132] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0133] In the foregoing description of this specification, references to terms such as "one embodiment," "another embodiment," or "some embodiments" indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0134] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

[0135] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the above embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A charging and discharging control method based on a DC microgrid, characterized in that, Includes the following steps: Determine whether the DC microgrid is powered off; when the DC microgrid is powered off, provide emergency power to the load devices in the DC microgrid through the available stored electrical energy of the energy storage element. When the DC microgrid is not powered off, it is determined whether the load feedback power is greater than the load consumption power. If the load feedback power is greater than the load consumption power, energy is recovered through the energy storage element. When the load operating power is greater than or equal to the transformer's rated power, the transformer's rated power is compensated. When the load operating power is less than the transformer's rated power, the energy storage element is charged during the off-peak hours of the AC power grid and discharged during the peak hours of the AC power grid. The step of compensating for the rated power of the transformer specifically includes: The device operating power of the load equipment and the rated power of the transformer in the DC microgrid are obtained. When the device operating power is greater than or equal to the rated power of the transformer, the first discharge power of the energy storage element is calculated based on the device operating power and the rated power of the transformer. The first discharge duration of the energy storage element is calculated based on the first discharge power and the available stored electrical energy of the energy storage element, and the first operating duration preset by the load device is obtained. When the first discharge duration is greater than or equal to the first operating duration, the energy storage element is controlled to discharge according to the first discharge power. When the first discharge duration is less than the first operating duration, the operating priority of the load device is obtained, and several important loads are determined according to the operating priority. Then, the second discharge power of the energy storage element is calculated according to the important loads, and the second discharge duration of the energy storage element is determined. When the second discharge duration is greater than or equal to the first operating duration, the energy storage element is discharged according to the second discharge power; If the second discharge duration is less than the first running duration, return to the step of determining several important loads based on the running priority, until the optimized second discharge duration is greater than or equal to the first running duration.

2. The charging and discharging control method based on a DC microgrid according to claim 1, characterized in that, The step of providing emergency power to the load devices in the DC microgrid through the available stored electrical energy of the energy storage element specifically includes: Obtain the available stored electrical energy of the energy storage element; The first total electrical energy required for the operation of the load device is determined based on the power of the load device and the preset first operating time. When the available stored electrical energy is greater than or equal to the first total electrical energy, emergency power is supplied to the load device through the available stored electrical energy; When the available stored power is less than the first total power, the operating priority of the load device is obtained, and several important loads are determined according to the operating priority, thereby determining the second total power required for the operation of the important loads; When the available stored electrical energy is greater than or equal to the second total electrical energy, emergency power is supplied to the critical load through the available stored electrical energy; If the available stored power is less than the second total power, return to the step of determining several important loads based on the running priority, until the available stored power is greater than or equal to the optimized second total power.

3. The charging and discharging control method based on a DC microgrid according to claim 1, characterized in that, The step of recovering electrical energy through the energy storage element specifically includes: When power utilization is prioritized, the load feedback power of the load device and the absorbable power of the energy storage element are obtained in the current time period, and it is determined whether the absorbable power is less than the load feedback power. When the absorbable electrical energy is greater than or equal to the load feedback electrical energy, the energy storage element is charged through the load feedback electrical energy until the available stored electrical energy of the energy storage element reaches a preset first threshold. When the absorbable energy is less than the load feedback energy, the discharge power and discharge duration of the energy storage element are determined, and the energy storage element is discharged according to the discharge power and the discharge duration. Then, after the discharge is completed, the absorbable energy of the energy storage element is updated until the updated absorbable energy is greater than or equal to the load feedback energy.

4. The charging and discharging control method based on a DC microgrid according to claim 1, characterized in that, The step of recovering electrical energy through the energy storage element specifically includes: When energy storage protection is prioritized, the load feedback energy of the load device and the absorbable energy of the energy storage element are obtained during the current period, and the first optimal charging power is calculated based on the absorbable energy. Based on the first optimal charging power, the energy storage element is charged by the load feedback power until the available stored energy of the energy storage element reaches a preset second threshold.

5. A charging and discharging control method based on a DC microgrid according to any one of claims 1 to 4, characterized in that, The step of charging the energy storage element during off-peak hours of the AC power grid specifically includes: Determine that the AC power grid is in a period of low electricity load, and obtain the rechargeable electrical energy of the energy storage element; Calculate the second optimal charging power of the energy storage element based on the rechargeable electrical energy; The energy storage element is charged according to the second optimal charging power until the available stored energy of the energy storage element reaches a preset third threshold.

6. The charging and discharging control method based on a DC microgrid according to claim 5, characterized in that, The step of discharging the energy storage element during peak load periods of the AC power grid specifically includes: Determine that the AC power grid is in a peak load period, and obtain the dischargeable electrical energy of the energy storage element; The optimal discharge power of the energy storage element is calculated based on the dischargeable electrical energy. The energy storage element is discharged according to the optimal discharge power until the available stored energy of the energy storage element reaches a preset fourth threshold.

7. A charging and discharging control system based on a DC microgrid, characterized in that, A method for implementing a charge / discharge control based on a DC microgrid as described in any one of claims 1 to 6 includes: An emergency power supply module is used to determine whether the DC microgrid is powered off. When the DC microgrid is powered off, it provides emergency power to the load devices in the DC microgrid through the available stored electrical energy of the energy storage element. The energy recovery module is used to determine whether the load feedback power is greater than the load consumption power when the DC microgrid is not interrupted; if the load feedback power is greater than the load consumption power, energy is recovered through the energy storage element. The power compensation module is used to compensate for the rated power of the transformer when the operating power of the load is greater than or equal to the rated power of the transformer. The power time-shifting module is used to charge the energy storage element during off-peak hours of the AC power grid when the load operating power is less than the transformer's rated power, and to discharge the energy storage element during peak hours of the AC power grid.

8. A charging and discharging control device based on a DC microgrid, characterized in that, include: At least one processor; At least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor implements a charging and discharging control method based on a DC microgrid as described in any one of claims 1 to 6.

9. A computer-readable storage medium storing a processor-executable program, characterized in that, The program executable by the processor is used, when executed by the processor, to perform a charging and discharging control method based on a DC microgrid as described in any one of claims 1 to 6.

Images