Off-grid source network load storage power distribution complete equipment

Abstract

The utility model discloses off-grid type source network load storage and distribution complete equipment. Alternating current power supply equipment provides alternating current power supply for all AC / DC converters through an alternating current collection unit; the AC / DC converters, the quick change-over switches and the direct-current loads are the same in number and correspond to one another, one end of each AC / DC converter is connected with the alternating-current collection unit, the other end of each AC / DC converter is connected with the first input end of the corresponding quick change-over switch, and the second input end of each quick change-over switch is connected with the direct-current bypass unit; the output end of the quick change-over switch is connected with the corresponding direct-current load; the output end of the quick change-over switch is also connected to the direct current collection unit; the DC power supply device is connected to the DC collection unit through the anti-countercurrent conduction device. The equipment has the functions of medium-voltage alternating current access, low-voltage direct current bypass switching and low-voltage direct current load output. The operation flexibility and reliability of the off-grid source network load storage power distribution network are improved, and the harmonic suppression and reactive compensation requirements of the off-grid source network load storage power distribution complete equipment are met.

Description

Technical Field

[0001] The utility model belongs to the technical field of off-grid source-network-load-storage project construction, and particularly relates to a technology for improving the reliability and flexibility of an off-grid source-network-load-storage power distribution system by means of a new type of off-grid source-network-load-storage power distribution complete set of equipment during the electrical topology construction of the source-network-load-storage project. Background Art

[0002] The off-grid source-network-load-storage power distribution complete set of equipment is a power transmission and transformation equipment solution that does not rely on a large power grid and combines renewable energy, a power system, a load, and an energy storage system. The source refers to the power source of renewable energy, the network refers to the power transmission network, the load refers to the electrical load, and the storage refers to the energy storage system. Through the source-network-load-storage technology, the volatility of renewable energy is smoothed, and the energy supply is more flexible and reliable.

[0003] Compared with the traditional grid-connected distribution network, the power source of the off-grid distribution network has changed from a traditional synchronous machine to a power electronic converter device. At the same time, the traditional distribution network does not consider the active regulation problem of the load too much. However, the off-grid distribution network needs to pay attention to the load following the source and better adapt to the characteristics of the power source by actively regulating the response of the load.

[0004] In the traditional off-grid source-network-load-storage power distribution complete set of equipment solutions, the following disadvantages exist:

[0005] (1) Due to the complex equipment of the AC / DC converter, the reliability is relatively low, and the probability of load loss due to equipment failure increases.

[0006] (2) Based on the traditional power frequency AC system solution, large power frequency transformers, large-capacity reactive power compensation equipment, etc. are configured, resulting in low transfer efficiency from the power source to the load and weak control performance.

[0007] (3) The traditional off-grid source-network-load-storage power distribution complete set of equipment solutions generally consider building the overall system capacity only by an AC system or a DC system, and do not give full play to the advantages of low cost and high efficiency of the medium-voltage DC solution. Content of the Utility Model

[0008] The purpose of the utility model is to provide an off-grid source-network-load-storage power distribution complete set of equipment, which has the functions of medium-voltage AC access, low-voltage DC bypass switching, and low-voltage DC load output. It improves the flexibility and reliability of the operation of the off-grid source-network-load-storage power distribution network and meets the requirements of harmonic governance and reactive power compensation of the off-grid source-network-load-storage power distribution complete set of equipment.

[0009] To achieve the above object, the solution of the present invention is:

[0010] An off-grid power generation, grid connection, load, energy storage and power distribution complete set of equipment, including at least one AC power supply device, one or more AC / DC converters, one or more DC loads, one or more fast switching switches, at least one DC power supply device, at least one anti-backflow conduction device, an AC energy storage system, an AC collection unit, a DC bypass unit and a DC collection unit;

[0011] The AC power supply device provides AC power for all AC / DC converters through the AC collection unit;

[0012] The number of the AC / DC converters, fast switching switches and DC loads is the same and corresponding. Among them, one end of each AC / DC converter is connected to the AC collection unit, and the other end is connected to the first input end of the corresponding fast switching switch. The second input end of the fast switching switch is connected to the DC bypass unit, and the output end of the fast switching switch is connected to the corresponding DC load;

[0013] The output end of the fast switching switch is also connected to the DC collection unit;

[0014] The DC power supply device is connected to the DC collection unit through the anti-backflow conduction device.

[0015] The above AC / DC converter adopts an isolated converter topology. Its AC input end adopts industrial frequency AC, a high-frequency isolation transformer is arranged inside, and the output end is DC direct current.

[0016] The above fast switching switch includes first to fourth reverse blocking triode thyristors and first to fourth bypass switches. Among them, the first to fourth reverse blocking triode thyristors are connected in parallel with the first to fourth bypass switches one by one; the anode of the first reverse blocking triode thyristor is used as the first input positive end of the fast switching switch, the anode of the third reverse blocking triode thyristor is used as the second input positive end of the fast switching switch, the cathodes of the first reverse blocking triode thyristor and the third reverse blocking triode thyristor are connected and used as the output negative end of the fast switching switch; the cathode of the second reverse blocking triode thyristor is used as the first input negative end of the fast switching switch, the cathode of the fourth reverse blocking triode thyristor is used as the second input negative end of the fast switching switch, and the anodes of the second reverse blocking triode thyristor and the fourth reverse blocking triode thyristor are connected and used as the output positive end of the fast switching switch.

[0017] After adopting the above scheme, the beneficial effects of the present utility model are:

[0018] (1) For the off-grid power generation, grid connection, load, energy storage and power distribution complete set of equipment of the present utility model, by configuring the AC / DC converter F1-2 with an isolated converter topology, the size and no-load energy consumption of the equipment are reduced, the system power transmission, dynamic reactive power compensation and active filtering are realized, and the conversion efficiency of the equipment is improved.

[0019] (2) The off-grid type source-network-load-storage power distribution complete equipment of the present utility model realizes the power supply transfer and switching during the failure of the converter by configuring the DC-side fast switching switch F1-5, improving the overall reliability of the equipment.

[0020] (3) The off-grid type source-network-load-storage power distribution complete equipment of the present utility model has the function of hierarchical access of DC equipment. Through the anti-backflow conduction device F1-6, the near-end new energy power supply can be accessed nearby and the fault interval can be isolated. Compared with the AC scheme, the access scheme is simplified and the overall investment of the equipment is reduced. Description of the Drawings

[0021] Figure 1 is the network topology diagram of the present utility model;

[0022] Figure 2 is the equipment schematic diagram of the fast switch in the present utility model. Detailed Embodiment

[0023] Hereinafter, the technical solutions and beneficial effects of the present invention will be described in detail with reference to the drawings.

[0024] As Figure 1 shown, the present utility model provides an off-grid type source-network-load-storage power distribution complete equipment F1, which includes at least one AC power supply device F1-1, one or more AC / DC converters F1-2, one or more DC loads F1-3, one or more fast switching switches F1-4, at least one DC power supply device F1-5, at least one anti-backflow conduction device F1-6, one AC energy storage system F1-7, one AC collection unit F1-8, one DC bypass unit F1-10 and one DC collection unit F1-9, which will be introduced separately below.

[0025] The AC power supply device F1-1 and the DC power supply device F1-5 provide AC and DC power inputs for the entire equipment.

[0026] In this embodiment, the number of AC / DC converters F1-2 is the same as and corresponds one-to-one to the number of fast switching switches F1-4. One end of the AC / DC converter F1-2 is connected to the AC collection unit F1-8, and the other end is connected to the corresponding fast switching switch F1-4.

[0027] In this embodiment, the AC / DC converter F1-2 adopts an isolated converter topology. The AC input end uses industrial frequency AC, and a high-frequency isolation transformer is arranged inside. The output end is DC direct current. The AC / DC converter F1-2 can perform function switching according to prefabricated strategies and loop requirements to achieve fault isolation, AC-DC conversion, active filtering, reactive power compensation and standby converter functions.

[0028] In this embodiment, in cooperation withFigure 2 The fast switching switch F1-4 adopts a fast unidirectional switch conduction structure, including first to fourth reverse blocking triode thyristors T1-T4 and first to fourth bypass switches K1-K4. Among them, the reverse blocking triode thyristors and the bypass switches are connected in parallel one by one. The anode of T1 serves as the first input positive terminal of the fast switching switch F1-4, the anode of T3 serves as the second input positive terminal of the fast switching switch F1-4, the cathodes of T1 and T3 are connected and serve as the output negative terminal of the fast switching switch F1-4; the cathode of T2 serves as the first input negative terminal of the fast switching switch F1-4, the cathode of T4 serves as the second input negative terminal of the fast switching switch F1-4, and the anodes of T2 and T4 are connected and serve as the output positive terminal of the fast switching switch F1-4.

[0029] In this embodiment, the number of fast switching switches F1-4 is the same as and corresponds one by one to the number of DC loads F1-3. The input side of the fast switching switch F1-4 is connected to the AC / DC converter F1-2 and the DC bypass unit F1-10, and the output side is connected to the DC load F1-3. Specifically, the first input positive terminal and the first input negative terminal of the fast switching switch F1-4 are respectively connected to the output positive pole and the output negative pole of the AC / DC converter F1-2 (see the input one in Figure 2 ), the second input positive terminal and the second input negative terminal of the fast switching switch F1-4 are respectively connected to the output positive pole and the output negative pole of the DC bypass unit F1-10 (see the input two in Figure 2 ), and the output positive terminal and the output negative terminal of the fast switching switch F1-4 are respectively connected to the input positive pole and the input negative pole of the DC load F1-3.

[0030] The anti-backflow conduction device F1-6 enables the power flow to only be transmitted unidirectionally from the DC power supply device F1-5 to the DC collection unit F1-9, thereby achieving reverse isolation.

[0031] In this embodiment, under normal conditions, the AC / DC converter F1-2 supplies power to the DC load F1-3 through the fast switching switch F1-4, and at the same time, one or more AC / DC converters F1-2 are put into the active filtering or reactive power compensation function. When a certain AC / DC converter F1-2 fails, the AC / DC converter F1-2 automatically locks, the fast switching switch F1-4 cuts off the circuit of the AC / DC converter F1-2, and switches to the DC bypass unit F1-10. At the same time, a standby AC / DC converter F1-2 in the device is put into the AC / DC conversion mode for load transfer.

[0032] In this embodiment, the DC power supply device F1-5 is connected to the DC collection unit F1-9 through the anti-reverse flow conduction device F1-6. When the new energy is generated, the DC power supply device F1-5 can establish a higher DC voltage than the DC collection unit F1-9, and the anti-reverse flow conduction device F1-6 is turned on. When the new energy fluctuates downward or even stops, the anti-reverse flow conduction device F1-6 is reversely non-conductive, thereby achieving flexible access and isolation of new energy. When a branch fails, the anti-reverse flow conduction device reversely locks and stops operating, and the non-fault branch is basically unaffected, with strong continuous operation capability, higher reliability, and lower construction cost.

[0033] The above embodiments are only for illustrating the technical idea of ​​the present utility model, and cannot be used to limit the protection scope of the present utility model. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present utility model shall fall within the protection scope of the present utility model.

Claims

1. An off-grid source-grid-load-storage-distribution complete set of equipment, characterized by: It includes at least one AC power supply device, one or more AC / DC converters, one or more DC loads, one or more fast switching switches, at least one DC power supply device, at least one anti-reverse current conduction device, an AC energy storage system, an AC collection unit, a DC bypass unit and a DC collection unit; The AC power supply device provides AC power to all AC / DC converters through an AC collection unit; The number of the AC / DC converters, fast switching switches, and DC loads is the same and corresponding, wherein one end of each AC / DC converter is connected to the AC collection unit, and the other end is connected to the first input end of the corresponding fast switching switch, the second input end of the fast switching switch is connected to the DC bypass unit, and the output end of the fast switching switch is connected to the corresponding DC load; The output end of the fast switching switch is also connected to a DC collection unit; The DC power supply device is connected to the DC collection unit through a reverse current prevention conduction device.

2. An off-grid source-grid-load-storage-distribution complete set of equipment as claimed in claim 1, characterized in that: The AC / DC converter adopts an isolated converter topology, an AC input end thereof adopts industrial frequency alternating current, a high-frequency isolation transformer is arranged inside, and an output end thereof is DC direct current.

3. The off-grid source-grid-load-storage-distribution complete set of equipment as claimed in claim 1, characterized in that: The fast switching switch includes first to fourth reverse blocking triode thyristors and first to fourth bypass switches, wherein the first to fourth reverse blocking triode thyristors are connected in parallel with the first to fourth bypass switches in a one-to-one correspondence; the anode of the first reverse blocking triode thyristor serves as the first positive input terminal of the fast switching switch, the anode of the third reverse blocking triode thyristor serves as the second positive input terminal of the fast switching switch, the cathode of the first reverse blocking triode thyristor is connected to the cathode of the third reverse blocking triode thyristor, and serves as the negative output terminal of the fast switching switch; the cathode of the second reverse blocking triode thyristor serves as the first negative input terminal of the fast switching switch, the cathode of the fourth reverse blocking triode thyristor serves as the second negative input terminal of the fast switching switch, the anode of the second reverse blocking triode thyristor is connected to the anode of the fourth reverse blocking triode thyristor, and serves as the positive output terminal of the fast switching switch.

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