A multi-energy complementary-based net micro-grid and plug-and-play energy storage system

Abstract

The application discloses a fishery rack micro-grid and plug-and-play energy storage system based on multi-energy complementation, comprising a DC bus, a tie switch, an interconnection converter, a power generation unit, a load unit and an energy storage unit; the load unit comprises an AC load and a DC load; the interconnection converter, the DC load, the power generation unit and the energy storage unit are connected to both DC buses; the DC input end of the interconnection converter is connected to the DC bus, the AC output end of the interconnection converter is connected to the AC load, the DC output ends of the interconnection converters are connected to the DC bus, and the DC output ends of the interconnection converters on both sides are connected to the DC input end of the interconnection converter on the other side through power transmission lines and the tie switch. The application adopts AC / DC hybrid micro-grid schemes respectively, takes into account the advantages of AC micro-grids and DC micro-grids, is suitable for more types of distributed power and loads, can be flexibly connected to the system, reduces the power conversion link, and improves the power supply reliability and economy of the micro-grid.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of micro-grid, in particular to a fishing raft micro-grid based on multi-energy complementation and a plug-and-play energy storage system. BACKGROUND

[0002] The electrification of existing offshore fishing rafts faces a series of severe challenges. The electrification of fishing vessels needs to first solve the problem of green energy supply in offshore environments. Under the conditions of off-shore environment and investment return rate priority, a green energy micro-grid technical solution is proposed for various offshore fishing rafts, which can be popularized. In the early stage of electrification industry, the layout of charging facilities is optimized, the technical correlation of the "supply-use-charge-line" energy chain is explored, and the "raft-ship-net" linkage and collaborative operation mechanism is constructed to improve the power supply guarantee capability; the intelligent operation and maintenance level is improved to increase the enthusiasm of users for electrification.

[0003] Under off-shore conditions, the reliability of the fishing raft micro-grid and the plug-and-play energy storage system is crucial. If the power grid fails, it will directly affect the normal use of electricity by off-shore users. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a fishing raft micro-grid based on multi-energy complementation and a plug-and-play energy storage system to solve the problems of the prior art.

[0005] To solve the above technical problems, the present application provides a fishing raft micro-grid based on multi-energy complementation and a plug-and-play energy storage system, which comprises a DC bus, a tie switch, an interconnection converter, a power generation unit, a load unit and an energy storage unit.

[0006] The load unit comprises an AC load and a DC load.

[0007] Two DC buses are connected to the interconnection converter, the DC load, the power generation unit and the energy storage unit.

[0008] The interconnection converter comprises a DC input end, a DC output end and an AC output end, the DC input end of the interconnection converter is connected to the DC bus, the AC output end of the interconnection converter is connected to the AC load, the DC output end of the interconnection converter is connected to the DC bus, and the DC output end of the interconnection converter on both sides is connected to the DC input end of the interconnection converter on the other side through a power transmission line and a tie switch.

[0009] Further, the DC load is connected to the DC bus through a DC / DC unidirectional converter.

[0010] Further, the DC load comprises a DC charging pile.

[0011] Further, the power generation unit comprises a wind power generation unit and a photovoltaic power generation unit, and the wind power generation unit and the photovoltaic power generation unit are connected to the DC bus through DC / DC unidirectional converters.

[0012] Further, the energy storage unit comprises a hydrogen energy storage unit, an ammonia hydrogen energy storage unit and a lithium battery energy storage unit, and the lithium battery energy storage unit is composed of a plurality of 2.5-degree lithium battery modules.

[0013] Further, the interconnection converter comprises a first converter and a second converter, and the first converter and the second converter each comprise a DC input end, a DC output end and an AC output end.

[0014] The AC input ends of the first converter and the second converter are connected to an AC load, the DC input ends of the first converter and the second converter are connected to the DC bus, and the DC output end of the second converter is connected to the DC input end of the first converter in the other interconnection converter through a transmission line and a tie switch.

[0015] The above technical scheme is adopted in the present application, and the following beneficial effects are achieved:

[0016] The multi-energy complementary fishing net micro-grid and plug-and-play energy storage system provided by the present application can realize distributed power generation, provide green power to offshore fishing net users, improve distributed energy conversion efficiency, and promote the construction of offshore fishing nets into a harmonious, ecological and environmentally friendly sustainable development purpose offshore aquaculture base.

[0017] The AC / DC hybrid micro-grid scheme is adopted in the present application, the hybrid micro-grid is composed of an AC sub-grid, a DC sub-grid and an interconnection converter connecting the two sub-grids, the advantages of AC micro-grid and DC micro-grid are considered, more types of distributed power and load are adapted, the system can be flexibly accessed, the power conversion link is reduced, the micro-grid power supply reliability and economy are improved.

[0018] When the two-side micro-grids are independently operated, the micro-grid ensures the stable operation of the off-grid micro-grid through the first converter (the second converter as a backup) in the interconnection converter, and the reliability of the system is improved.

[0019] When microgrid 1 requires energy exchange from microgrid 2, microgrid 1 maintains its original operating state, while the second converter in microgrid 2 operates to ensure energy transfer from microgrid 2 to microgrid 1. Meanwhile, converter 1 in microgrid 2 maintains its original operating state to ensure normal power supply to the load of microgrid 2, thus ensuring the normal operation of both microgrids and improving the overall system reliability. Furthermore, microgrid 1 and microgrid 2 are interconnected via DC, reducing energy exchange losses between them. Attached Figure Description

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0021] Figure 1 This is a schematic diagram of a fish farm microgrid and a plug-and-play energy storage system based on multi-energy complementarity.

[0022] The labels in the attached diagram are as follows:

[0023] DC bus-1; tie switch-2; AC load-3; DC load-4; interconnected converter-5; DC charging pile-6; wind power generation unit-7; photovoltaic power generation unit-8; lithium battery energy storage unit-9; first converter-51; second converter-52. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0025] See attached document Figure 1 As shown, the present invention provides a fish farm microgrid and plug-and-play energy storage system based on multi-energy complementarity, including a DC bus 1, a tie switch 2, an interconnected converter 5, a power generation unit, a load unit and an energy storage unit.

[0026] For ease of understanding, the two microgrids will be defined as microgrid 1 and microgrid 2 respectively below.

[0027] The load unit includes an AC load 3 (e.g., AC charging pile, mains power, etc.) and a DC load 4 (e.g., DC charging pile 6); both DC buses 1 are connected to interconnected converters 5, DC loads 4, power generation units, and energy storage units. The DC loads are connected to DC bus 1 via a DC / DC unidirectional converter; the power generation units include a wind power generation unit 7 and a photovoltaic power generation unit 8, which are connected to DC bus 1 via a DC / DC unidirectional converter.

[0028] In this embodiment, the energy storage unit includes a hydrogen energy storage unit, an ammonia hydrogen energy storage unit, and a lithium battery energy storage unit 9. Specifically, the microgrid 1 and the microgrid 2 use lithium battery energy storage units that can be plugged in and used. A single lithium battery module is 2.5 degrees of electricity, lightweight, easy to transport, easy to plug in, and overcomes the technical difficulties of large-scale small-capacity distributed energy storage access, management, and scheduling. The lithium battery energy storage units of the microgrid 1 and the microgrid 2 can be plugged in and out with adjacent energy storage units on the fishing raft, realizing cross-fishing raft energy consumption.

[0029] In addition, the microgrid 2 is also configured with a hydrogen energy storage and an ammonia hydrogen energy storage unit (not shown in the figure) compared with the microgrid 1. The hydrogen storage equipment, hydrogen combustion unit or fuel cell is combined with excess wind power and photovoltaic to realize long-term storage and conversion of wind power and photovoltaic, effectively guaranteeing the sustainable development and utilization of new energy. In the absence of wind and light, the ammonia hydrogen energy storage system replaces the diesel generator set, reduces the adverse effects on the ecological environment of residents' life and islands, and greatly reduces noise and environmental pollution.

[0030] The above-mentioned interconnection converter 5 includes a direct current input end, a direct current output end and an alternating current output end. The direct current input end of the interconnection converter 5 is connected to the direct current bus 1, the alternating current output end of the interconnection converter 5 is connected to the alternating current load 3, and the direct current output end of the interconnection converter 5 is connected to the direct current bus 1. The direct current output end of the interconnection converter 5 on both sides is connected to the direct current input end of the interconnection converter 5 on the other side through the power transmission line and the tie switch 2. When the microgrid 1 needs energy from the microgrid 2, the tie switch 2 is connected, and the interconnection converter 5 in the microgrid 2 transmits energy to the microgrid 1, ensuring stable operation of the microgrid on both sides and improving the reliability of the system.

[0031] In this embodiment, the interconnection converter 5 includes a first converter 51 and a second converter 52, both of which include a direct current input end, a direct current output end and an alternating current output end. The alternating current input end of the first converter 51 and the second converter 52 is connected to the alternating current load 3, the direct current input end of the first converter 51 and the second converter 52 is connected to the direct current bus 1, and the direct current output end of the second converter 52 is connected to the direct current input end of the first converter 51 in the interconnection converter 5 on the other side through the power transmission line and the tie switch 2.

[0032] When the micro-grid 1 and the micro-grid 2 are independently operated, the DC bus 1 DC power is supplied to the AC load 3 through the first converter 51. The micro-grid 1 and the micro-grid 2 are respectively ensured to be stably operated by the first converter 51 (the second converter 52 as a backup) in the interconnection converter 5. The AC-DC hybrid micro-grid scheme is adopted in the application, the hybrid micro-grid is composed of an AC sub-network, a DC sub-network and an interconnection converter 5 connecting the two sub-networks, the advantages of the AC micro-grid and the DC micro-grid are considered, more types of distributed power and loads are adapted, the system can be flexibly accessed, the power conversion link is reduced, the micro-grid power supply reliability and economy are improved.

[0033] When the micro-grid 1 needs the micro-grid 2 to perform energy interconnection, the micro-grid 1 remains the original operating state, the tie switch 2 is turned on, and the second converter 52 in the micro-grid 2 works, the second converter 52 transmits the power on the DC bus 1 in the micro-grid 2 to the input end of the first converter 51 in the micro-grid 1, and the first converter 51 outputs the input DC to the DC bus 1 or converts it into AC power to supply the AC load 3, so as to ensure the energy transmission of the micro-grid 2 to the micro-grid 1. During this period, the first converter 51 in the micro-grid 2 maintains the original operating state, ensures the normal power supply to the load of the micro-grid 2, and ensures the normal operation of the two micro-grids, and improves the reliability of the whole system. The micro-grid 1 and the micro-grid 2 are interconnected through DC, which effectively reduces the energy interconnection loss between the micro-grid 1 and the micro-grid 2.

[0034] The above is the embodiment of the application, for those skilled in the art, according to the teaching of the application, any equivalent change, modification, replacement and variation made within the scope of the application should be included in the scope of the application.

Claims

1. A fish farm microgrid and plug-and-play energy storage system based on multi-energy complementarity, characterized in that, Includes DC bus (1), interconnection switch (2), interconnection converter (5), power generation unit, load unit and energy storage unit; The load unit includes an AC load (3) and a DC load (4). Both DC bus (1) are connected to interconnected converter (5), DC load (4), power generation unit and energy storage unit; The interconnected converter (5) includes a DC input terminal, a DC output terminal and an AC output terminal; the DC input terminal of the interconnected converter (5) is connected to the DC bus (1), the AC output terminal of the interconnected converter (5) is connected to the AC load (3), the DC output terminals of the interconnected converter (5) are all connected to the DC bus (1), and the DC output terminals of the interconnected converters (5) on both sides are connected to the DC input terminal of the interconnected converter (5) on the other side through the transmission line and the connecting switch (2); The interconnected converter (5) includes a first converter (51) and a second converter (52), both of which include a DC input terminal, a DC output terminal and an AC output terminal; The AC output terminals of the first converter (51) and the second converter (52) are both connected to the AC load (3). The DC input terminals of the first converter (51) and the second converter (52) are both connected to the DC bus (1). The DC output terminal of the second converter (52) is connected to the DC input terminal of the first converter (51) in the other interconnected converter (5) through the power transmission line and the interconnection switch (2).

2. The fish raft microgrid and plug-and-play energy storage system based on multi-energy complementarity according to claim 1, characterized in that, The DC load is connected to the DC bus (1) via a DC / DC unidirectional converter.

3. The fish raft microgrid and plug-and-play energy storage system based on multi-energy complementarity according to claim 1, characterized in that, The DC load (4) includes a DC charging pile (6).

4. The fish raft microgrid and plug-and-play energy storage system based on multi-energy complementarity according to claim 1, characterized in that, The power generation unit includes a wind power generation unit (7) and a photovoltaic power generation unit (8), both of which are connected to the DC bus (1) via a DC / DC unidirectional converter.

5. The fish raft microgrid and plug-and-play energy storage system based on multi-energy complementarity according to claim 1, characterized in that, The energy storage unit includes a hydrogen energy storage unit, an ammonia-hydrogen energy storage unit, and a lithium battery energy storage unit (9). The lithium battery energy storage unit (9) is composed of multiple 2.5 kWh lithium battery modules.

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