Distributed energy storage system of micro-grid and energy management method

Abstract

The invention discloses a distributed energy storage system and an energy management method of a micro-grid, and the system comprises a plurality of distributed energy storage units which are connected in an annular topological structure through cables and are used for storing electric energy; a control subsystem is carried on each distributed energy storage unit; the control subsystem comprises an energy transmission unit, an energy conversion unit and a self-repairing unit; the energy transmission unit is used for controlling the charging and discharging operation of each distributed energy storage unit to supply power to an electric energy load in the micro-grid; the energy conversion unit is used for converting the electric energy stored in each distributed energy storage unit into heat energy, mechanical energy and / or light energy, so as to supply power to a heat energy load, a mechanical energy load and / or a light energy load in the micro-grid; and the self-repairing unit is used for monitoring and maintaining the health state of the distributed energy storage unit. Through the system, the energy storage cost can be reduced, the energy resource waste is reduced, the energy conversion efficiency is improved, and the service life of the distributed energy storage unit is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of microgrids, and more particularly to a distributed energy storage system and energy management method for microgrids. Background Art

[0002] With the growing global demand for renewable energy and the urgent need to transform the traditional energy structure, microgrids have attracted widespread attention as a flexible and efficient power supply solution. Microgrids can operate independently of the main grid to a certain extent by integrating localized power generation resources (such as solar photovoltaic panels, wind turbines, etc.), loads and control systems, and can be connected to it when necessary, thereby improving the flexibility and reliability of the entire power system. Among them, distributed energy storage systems, as one of the key components of microgrids, play an important role in energy balance, frequency regulation, peak shaving and valley filling.

[0003] However, although existing microgrid energy storage technologies and energy management methods have made significant progress in many aspects, they still face a series of challenges in practical application:

[0004] 1. The initial investment cost of mainstream energy storage solutions on the current market, such as lithium-ion batteries, is relatively high. In addition, since microgrids usually rely on relatively small and decentralized power supply points, their overall reliability and stability are easily affected by the failure of a single component.

[0005] 2. Under changing working conditions, the current microgrid energy storage technology and energy management methods lack effective energy management and scheduling mechanisms, which may lead to waste of resources or fail to meet the needs of critical loads.

[0006] 3. In addition to electricity, modern communities and industrial facilities may also require different forms of energy supply, such as thermal energy, mechanical energy, and even light energy. The traditional single form of energy supply is difficult to flexibly respond to such diverse demand scenarios.

[0007] 4. Frequent use will shorten the battery life and increase the cost burden of long-term operation. In addition, under high-density storage conditions, safety accidents may occur due to overheating or other reasons.

[0008] To sum up, how to reduce energy storage costs, reduce energy resource waste, improve energy conversion efficiency, extend service life and ensure safety, so as to promote the advancement of microgrid technology, is an urgent problem that technicians in this field need to solve. Summary of the invention

[0009] In view of the above problems, the present invention provides a distributed energy storage system and energy management method for a microgrid to at least solve some of the technical problems mentioned in the above background technology.

[0010] In order to achieve the above object, the present invention adopts the following technical solution:

[0011] In one aspect, the present invention provides a distributed energy storage system for a microgrid, comprising: a plurality of distributed energy storage units connected in a ring topology structure through cables, for storing electric energy;

[0012] The distributed energy storage unit is equipped with a control subsystem;

[0013] The control subsystem includes an energy transmission unit, an energy conversion unit and a self-repairing unit;

[0014] The energy transmission unit is respectively used to control the charging and discharging operation of each of the distributed energy storage units to supply power to the electric energy loads in the microgrid;

[0015] The energy conversion unit is used to convert the electrical energy stored in each of the distributed energy storage units into thermal energy, mechanical energy and / or light energy, so as to supply power to the thermal energy load, mechanical energy load and / or light energy load in the microgrid;

[0016] The self-repairing unit is used to monitor the health status of the distributed energy storage unit and perform maintenance.

[0017] Furthermore, each of the distributed energy storage units is composed of a plurality of battery modules;

[0018] The battery module is installed through a standardized interface;

[0019] The power input end of the battery module is provided with a rectifier regulator for converting alternating current into direct current for storage.

[0020] Further, the energy transmission unit includes a power demand acquisition module, an optimal path selection module and an inverter control module;

[0021] The power demand acquisition module is used to acquire multiple power loads with power demand in the microgrid, as well as the location, power consumption and power type corresponding to each of the power loads;

[0022] The optimal path selection module is used to select, for each of the electric energy loads, a distributed energy storage unit that meets the power consumption and is the shortest distance from the electric energy load as the optimal distributed energy storage unit to supply power to the electric energy load;

[0023] The inverter control module is used to control the inverter to convert the direct current in the optimal distributed energy storage unit into alternating current when the power consumption type of the electric energy load is alternating current.

[0024] Furthermore, the energy transmission unit further includes a power transmission determination module and a path reconfiguration module;

[0025] The power transmission judgment module is used to monitor the remaining power and power transmission stability of the optimal distributed energy storage unit in real time; and when the remaining power or power transmission stability is lower than the corresponding minimum threshold, the judgment result is sent to the path reconfiguration module;

[0026] The path reconfiguration module is used to re-screen suboptimal distributed energy storage units from distributed energy storage units that are not currently providing power supply services.

[0027] Further, the energy conversion unit includes an electric energy determination module, an energy demand acquisition module and an energy conversion module;

[0028] The electric energy judgment module is used to obtain the storage capacity of the distributed energy storage unit that is not in power supply service in real time; and when the storage capacity is greater than the maximum storage capacity threshold, the judgment result is sent to the energy conversion module;

[0029] The energy demand acquisition module is used to acquire other energy loads with other energy demands in the microgrid; the other energy demands include thermal energy demands, mechanical energy demands and / or light energy demands; and send the other energy demands to the energy conversion module;

[0030] The energy conversion module is used to perform corresponding energy conversion on the electrical energy exceeding the maximum storage threshold according to the other energy requirements.

[0031] Further, the self-repairing unit includes a thermal management module and a battery fluid replenishment module;

[0032] The thermal management module is used to regularly detect the temperature inside the distributed energy storage unit and deliver hot air or cold air to the distributed energy storage unit according to the detected temperature;

[0033] The battery liquid replenishing module is used to regularly detect the battery liquid content in each of the battery modules, and when the battery liquid content is lower than a preset content, control a preset battery liquid storage to replenish the battery liquid into the battery module.

[0034] On the other hand, the present invention provides a microgrid energy management method, which is applied to the above-mentioned distributed energy storage system, comprising the following steps:

[0035] Connecting multiple distributed energy storage units in a ring topology through cables to store electrical energy;

[0036] The charging and discharging operations, energy conversion operations and self-test operations of the distributed energy storage unit are regulated by the control subsystem carried by the distributed energy storage unit.

[0037] Furthermore, the charging and discharging operations of the distributed energy storage units are regulated, specifically including:

[0038] Acquire multiple electric energy loads with electricity demand in the microgrid, as well as the location, power consumption and type of electricity consumption corresponding to each of the electric energy loads;

[0039] For each of the electric energy loads, a distributed energy storage unit that meets the power consumption and is the shortest distance from the electric energy load is selected as the optimal distributed energy storage unit to supply power to the electric energy load;

[0040] When the power consumption type of the electric energy load is alternating current, the inverter is controlled to convert the direct current in the optimal distributed energy storage unit into alternating current.

[0041] Furthermore, the energy conversion operation of the distributed energy storage unit is regulated, specifically including:

[0042] Real-time acquisition of the storage capacity of distributed energy storage units that are not currently providing power;

[0043] Acquire other energy loads with other energy demands in the microgrid; the other energy demands include thermal energy demands, mechanical energy demands and / or light energy demands;

[0044] When the amount of stored electricity is greater than a maximum storage threshold, the electrical energy exceeding the maximum storage threshold is converted accordingly according to the other energy requirements.

[0045] Furthermore, the self-checking operation of the distributed energy storage unit is regulated, specifically including:

[0046] Regularly detecting the temperature inside the distributed energy storage unit, and delivering hot air or cold air to the distributed energy storage unit according to the detected temperature;

[0047] The battery liquid content in each of the battery modules is detected regularly, and when the battery liquid content is lower than a preset content, a preset battery liquid storage is controlled to replenish the battery liquid into the battery module.

[0048] It can be seen from the above technical solutions that, compared with the prior art, the present invention discloses a distributed energy storage system and energy management method for a microgrid, which has the following beneficial effects:

[0049] The distributed energy storage units in the present invention are connected in a ring topology structure, realizing a modular design, which not only facilitates the rapid replacement and maintenance of a single battery module, but also enhances the flexibility and scalability of the entire energy storage system.

[0050] In the present invention, the energy transmission unit in the control subsystem is used to dynamically adjust the power supply path according to the actual location and demand of the load, so that the entire microgrid is more flexible and a continuous and stable power supply is guaranteed.

[0051] The present invention realizes different forms of energy supply by controlling the energy conversion unit in the subsystem, which can improve the utilization rate of energy and achieve flexible response to diverse energy demand scenarios in the microgrid.

[0052] The present invention effectively increases the service life of the distributed energy storage unit by controlling the self-repair unit in the subsystem.

[0053] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0055] Figure 1 A schematic diagram of the framework of a distributed energy storage system for a microgrid provided in an embodiment of the present invention.

[0056] Figure 2 A schematic flow chart of a microgrid energy management method provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0057] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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 ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] Embodiment 1:

[0059] See also Figure 1 As shown, this embodiment discloses a distributed energy storage system of a microgrid, comprising: a plurality of distributed energy storage units connected in a ring topology structure through cables, for storing electric energy;

[0060] The distributed energy storage unit is equipped with a control subsystem;

[0061] The control subsystem includes an energy transmission unit, an energy conversion unit and a self-repairing unit;

[0062] The energy transmission unit is respectively used to control the charging and discharging operation of each distributed energy storage unit to supply power to the electric energy load in the microgrid;

[0063] An energy conversion unit, used to convert the electrical energy stored in each distributed energy storage unit into thermal energy, mechanical energy and / or light energy, so as to supply power to the thermal energy load, mechanical energy load and / or light energy load in the microgrid;

[0064] Self-repairing units are used to monitor the health status of distributed energy storage units and perform maintenance.

[0065] Next, each of the above units will be described in detail.

[0066] 1. Distributed energy storage units

[0067] Multiple distributed energy storage units are connected by cables in a ring topology and are used together to store electrical energy; each distributed energy storage unit consists of multiple battery modules; these battery modules are installed through standardized interfaces, ensuring the modular design of the system. Such a modular design not only facilitates the rapid replacement and maintenance of a single battery module, but also enhances the flexibility and scalability of the entire energy storage system. The application of standardized interfaces enables battery modules from different manufacturers to be seamlessly integrated into the system, thereby improving the compatibility and reliability of the system.

[0068] In addition, since each distributed energy storage unit is an independently working unit, when a distributed energy storage unit in the ring topology fails, it will not affect the operation of other distributed energy storage units, making it easy to replace or maintain them individually, reducing the overall operation and maintenance costs, while also improving the overall reliability and stability of the distributed energy storage system; in addition, this modular structure is conducive to the precise monitoring and control of the status of each battery module, realizing refined energy management and scheduling.

[0069] The power input end of the battery module is equipped with a rectifier regulator to convert AC power into DC power for storage; DC power is more suitable for the charging process of energy storage equipment, which can improve charging efficiency and reduce energy loss, which helps protect the battery from voltage fluctuations and extend its service life.

[0070] 2. Energy transfer unit

[0071] The energy transmission unit includes a power demand acquisition module, an optimal path selection module and an inverter control module; specifically:

[0072] The power demand acquisition module is used to acquire multiple power loads with power demand in the microgrid, as well as the location, power consumption and power type corresponding to each power load;

[0073] The optimal path selection module is used to select, for each electric energy load, a distributed energy storage unit that meets the power consumption and has the shortest distance to the electric energy load as the optimal distributed energy storage unit to supply power to the electric energy load;

[0074] The inverter module is used to control the inverter to convert the DC power in the optimal distributed energy storage unit into AC power when the power consumption type of the electric energy load is AC power.

[0075] Based on the above energy transmission unit, the power supply path can be dynamically adjusted according to the actual location and demand of the load, making the entire microgrid more flexible and able to quickly adapt to load changes; this instant response mechanism is particularly important for dealing with sudden peak power consumption or fault conditions. Through effective energy management and scheduling mechanisms, a continuous and stable power supply is guaranteed.

[0076] 3. Energy conversion unit

[0077] The energy conversion unit includes an electric energy judgment module, an energy demand acquisition module and an energy conversion module; specifically:

[0078] The electric energy judgment module is used to obtain the storage capacity of the distributed energy storage unit that is not currently providing power in the ring topology in real time; and when the storage capacity is greater than the maximum storage capacity threshold, the judgment result is sent to the energy conversion module;

[0079] An energy demand acquisition module is used to acquire other energy loads with other energy demands in the microgrid; other energy demands include thermal energy demands, mechanical energy demands and / or light energy demands; and send other energy demands to the energy conversion module;

[0080] The energy conversion module is used to perform corresponding energy conversion on the electrical energy exceeding the maximum storage threshold according to other energy requirements.

[0081] Through the energy conversion unit, different forms of energy supply can be achieved, which can improve energy utilization and achieve flexible response to diverse energy demand scenarios in the microgrid.

[0082] 4. Self-repair unit

[0083] The self-repairing unit includes a thermal management module and a battery fluid replenishment module; specifically:

[0084] The thermal management module is used to regularly detect the temperature inside the distributed energy storage unit and deliver hot or cold air to the distributed energy storage unit according to the detected temperature to prevent safety problems that may be caused by overheating or other reasons under high-density storage conditions;

[0085] The battery liquid replenishing module is used to regularly detect the battery liquid content in each battery module, and when the battery liquid content is lower than a preset content, control a preset battery liquid storage device to replenish the battery liquid into the battery module.

[0086] Embodiment 2:

[0087] On the basis of the above-mentioned embodiment 1, in the embodiment 2, the energy transmission unit further includes a power transmission judgment module and a path reconfiguration module; specifically:

[0088] The power transmission judgment module is used to monitor the remaining power and power transmission stability of the optimal distributed energy storage unit in real time; and when the remaining power or power transmission stability is lower than the corresponding minimum threshold, the judgment result is sent to the path reconfiguration module;

[0089] A path reconfiguration module, used to re-screen suboptimal distributed energy storage units from distributed energy storage units that are not currently providing power supply services;

[0090] Based on this, it is ensured that potential problems can be discovered in time at any time. Once insufficient remaining power or unstable power transmission is detected, measures can be taken quickly to avoid power outages in the entire system due to problems in a single energy storage unit.

[0091] Embodiment three:

[0092] Based on the above-mentioned embodiment one and / or embodiment two, in embodiment three, the energy transmission unit also includes an electric energy load importance comparison module, which is used to compare and sort the importance of the electric energy loads with useful electricity demand obtained by the electricity demand acquisition module, and allocate distributed energy storage units according to the priority of importance, to ensure that the needs of critical loads can be met first.

[0093] Embodiment 4:

[0094] Based on the above-mentioned embodiment 1, embodiment 2 and / or embodiment 3, in this embodiment 4, the energy conversion unit further includes other energy load final importance comparison module, which is used to compare and sort the importance of other energy loads with energy demand obtained by the energy demand acquisition module, and convert the electric energy according to the priority of the importance.

[0095] Embodiment five:

[0096] See also Figure 2 As shown, an embodiment of the present invention further provides an energy management method for a microgrid, which is applied to the above-mentioned distributed energy storage system, including: connecting multiple distributed energy storage units in a ring topology structure through cables to store electric energy; regulating the charging and discharging operations, energy conversion operations and self-test operations of the distributed energy storage units through a control subsystem carried by the distributed energy storage units; wherein:

[0097] The charging and discharging operations of the distributed energy storage units are regulated, specifically including: obtaining multiple electric energy loads with electricity demand in the microgrid, as well as the location, power consumption and type of electricity consumption corresponding to each electric energy load; for each electric energy load, selecting the distributed energy storage unit that meets the power consumption and has the shortest distance to the electric energy load as the optimal distributed energy storage unit to supply power to the electric energy load; when the power consumption type of the electric energy load is AC power, controlling the inverter to convert the DC power in the optimal distributed energy storage unit into AC power.

[0098] The energy conversion operation of the distributed energy storage unit is regulated, specifically including: real-time acquisition of the storage capacity of the distributed energy storage unit that is not currently providing power supply service; acquisition of other energy loads with other energy demands in the microgrid; other energy demands include thermal energy demand, mechanical energy demand and / or light energy demand; when the storage capacity is greater than the maximum storage threshold, corresponding energy conversion is performed on the electric energy that exceeds the maximum storage threshold according to other energy demands.

[0099] The self-test operation of the distributed energy storage unit is regulated, specifically including: regularly detecting the temperature inside the distributed energy storage unit, and delivering hot air or cold air to the inside of the distributed energy storage unit according to the detected temperature; regularly detecting the battery liquid content in each battery module, and when the battery liquid content is lower than the preset content, controlling the preset battery liquid reservoir to replenish the battery liquid into the battery module.

[0100] Embodiment six:

[0101] In the above embodiments 1 to 5, it is mentioned that power is supplied to the electric energy load in the microgrid. This embodiment 6 describes the case where the electric energy load in the microgrid is a car charging pile. An air conditioning subsystem is installed near the car charging pile. When the car starts charging, the air conditioning can be automatically turned on to preheat or precool the interior of the vehicle to ensure that the interior environment is comfortable when the user returns to the car.

[0102] The air conditioning regulation subsystem also includes a load monitoring module and a load balancing module; wherein the load monitoring module is used to monitor the stability of the charging power of the vehicle. When the stability is lower than the preset stability value, the power output of the air conditioner is adjusted through the load balancing module, for example, the working intensity of the air conditioner is reduced to give priority to the power supply of the charging pile;

[0103] The above-mentioned air conditioning subsystem also includes a remote control module. Based on the user port, the air conditioner can be controlled to start through the remote control module, which is convenient for users to operate by themselves, making the air conditioning subsystem more user-friendly.

[0104] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. As for the method disclosed in the embodiment, since it corresponds to the system disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description.

[0105] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A distributed energy storage system for a microgrid, characterized in that: include: A plurality of distributed energy storage units connected by cables in a ring topology structure for storing electrical energy; The distributed energy storage unit is equipped with a control subsystem; The control subsystem includes an energy transmission unit, an energy conversion unit and a self-repairing unit; The energy transmission unit is used to control the charging and discharging operations of each of the distributed energy storage units to supply power to the electrical energy loads in the microgrid; The energy conversion unit is used to convert the electrical energy stored in each of the distributed energy storage units into thermal energy, mechanical energy and / or light energy, so as to supply power to the thermal energy load, mechanical energy load and / or light energy load in the microgrid; The self-repairing unit is used to monitor the health status of the distributed energy storage unit and perform maintenance.

2. A distributed energy storage system for a microgrid according to claim 1, characterized in that: Each of the distributed energy storage units is composed of a plurality of battery modules; The battery module is installed through a standardized interface; The power input end of the battery module is provided with a rectifier regulator for converting alternating current into direct current for storage.

3. A distributed energy storage system for a microgrid according to claim 1, characterized in that: The energy transmission unit includes a power demand acquisition module, an optimal path selection module and an inverter control module; The power demand acquisition module is used to acquire multiple power loads with power demand in the microgrid, as well as the location, power consumption and power type corresponding to each of the power loads; The optimal path selection module is used to select, for each of the electric energy loads, a distributed energy storage unit that meets the power consumption and is the shortest distance from the electric energy load as the optimal distributed energy storage unit to supply power to the electric energy load; The inverter control module is used to control the inverter to convert the direct current in the optimal distributed energy storage unit into alternating current when the power consumption type of the electric energy load is alternating current.

4. A distributed energy storage system for a microgrid according to claim 3, characterized in that: The energy transmission unit also includes a power transmission judgment module and a path reconfiguration module; The power transmission judgment module is used to monitor the remaining power and power transmission stability of the optimal distributed energy storage unit in real time; and when the remaining power or power transmission stability is lower than a corresponding minimum threshold, sending a determination result to the path reconfiguration module; The path reconfiguration module is used to re-screen suboptimal distributed energy storage units from distributed energy storage units that are not currently providing power supply services.

5. A distributed energy storage system for a microgrid according to claim 1, characterized in that: The energy conversion unit includes an electric energy judgment module, an energy demand acquisition module and an energy conversion module; The electric energy judgment module is used to obtain the storage capacity of the distributed energy storage unit that is not in power supply service in real time; and when the storage capacity is greater than the maximum storage capacity threshold, the judgment result is sent to the energy conversion module; The energy demand acquisition module is used to acquire other energy loads with other energy demands in the microgrid; the other energy demands include thermal energy demands, mechanical energy demands and / or light energy demands; and send the other energy demands to the energy conversion module; The energy conversion module is used to perform corresponding energy conversion on the electrical energy exceeding the maximum storage threshold according to the other energy requirements.

6. A distributed energy storage system for a microgrid according to claim 2, characterized in that: The self-repairing unit includes a thermal management module and a battery fluid replenishment module; The thermal management module is used to periodically detect the temperature inside the distributed energy storage unit and deliver hot air or cold air to the distributed energy storage unit according to the detected temperature; The battery liquid replenishing module is used to regularly detect the battery liquid content in each of the battery modules, and when the battery liquid content is lower than a preset content, control a preset battery liquid storage to replenish the battery liquid into the battery module.

7. A method for energy management of a microgrid, characterized in that: Applied to the distributed energy storage system described in any one of claims 1-6, it realizes the regulation of the charging and discharging operation, energy conversion operation and self-test operation of the distributed energy storage unit.

8. The energy management method of a microgrid according to claim 7, characterized in that: Regulate the charging and discharging operations of distributed energy storage units, including: Acquire multiple electric energy loads with electricity demand in the microgrid, as well as the location, power consumption and type of electricity consumption corresponding to each of the electric energy loads; For each of the electric energy loads, a distributed energy storage unit that meets the power consumption and is the shortest distance from the electric energy load is selected as the optimal distributed energy storage unit to supply power to the electric energy load; When the power consumption type of the electric energy load is alternating current, the inverter is controlled to convert the direct current in the optimal distributed energy storage unit into alternating current.

9. The energy management method of a microgrid according to claim 7, characterized in that: Regulate the energy conversion operation of distributed energy storage units, including: Real-time acquisition of the storage capacity of distributed energy storage units that are not currently providing power; Acquire other energy loads with other energy demands in the microgrid; the other energy demands include thermal energy demands, mechanical energy demands and / or light energy demands; When the amount of stored electricity is greater than a maximum storage threshold, the electrical energy exceeding the maximum storage threshold is converted accordingly according to the other energy requirements.

10. The energy management method of a microgrid according to claim 7, characterized in that: Regulate the self-test operation of distributed energy storage units, including: Regularly detecting the temperature inside the distributed energy storage unit, and delivering hot air or cold air to the distributed energy storage unit according to the detected temperature; The battery liquid content in each of the battery modules is detected regularly, and when the battery liquid content is lower than a preset content, a preset battery liquid storage is controlled to replenish the battery liquid into the battery module.

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