System for accessing energy storage power station to power grid

Abstract

The utility model discloses a system for accessing an energy storage power station to a power grid, which relates to the technical field of power generation grid connection and comprises transformers, an energy storage power station and an access system for connecting the energy storage power station and the transformers, the transformers comprise a 1 # transformer and a 2 # transformer, and the access system comprises a grid-connected cabinet QA0, a grid-connected cabinet QA1 and a grid-connected cabinet QA2. The grid-connected cabinet QA1 is connected to a 10.5 kV bus of the 1 # transformer, and the grid-connected cabinet QA2 is connected to a 10.5 kV bus of the 2 # transformer. According to the utility model, the energy storage power station is connected to a power grid by adopting an access mode of the two transformers and the three grid-connected cabinets, and the residual capacity of the 1 # main transformer and the residual capacity of the 2 # main transformer are compared; and the low-voltage side of the 1 # main transformer and the low-voltage side of the 2 # main transformer can absorb the electrical load of the discharge capacity of the energy storage power station, so that the charging path of the 1 # transformer and the 2 # transformer to the energy storage power station and the discharge path of the energy storage power station are controlled, the capacity configuration of the energy storage power station is maximized, and the power utilization cost of an enterprise is further reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of power generation and grid connection, and in particular to a system for connecting an energy storage power station to a power grid. Background Art

[0002] At present, there are more and more user-side energy storage power stations in China, and the business model they adopt is generally "self-generation and self-use" (energy storage power stations charge when electricity prices are low, and discharge for enterprise production when electricity prices are high, and excess electricity is not allowed to be connected to the grid), reducing the electricity costs of enterprises by taking advantage of the peak-valley electricity price difference. User-side energy storage power stations are generally connected to the low-voltage side (10.5kV) of the enterprise's main transformer, and the capacity depends on the remaining capacity of the main transformer and the power load (when the electricity price is low, the main transformer should have enough remaining capacity for the energy storage power station to charge, and when the electricity price is high, there should be enough power load to absorb the discharge of the energy storage power station). However, the larger the capacity of the energy storage power station, the lower the static investment per unit capacity; for enterprises with two or more main transformers, it is necessary to reasonably design the access method of the energy storage power station and the charge and discharge control method after access to maximize the capacity configuration of the energy storage power station, which is more conducive to reducing the electricity costs of enterprises. Utility Model Content

[0003] The purpose of the utility model is to provide a system for connecting an energy storage power station to a power grid, so as to solve the problems existing in the prior art mentioned in the above background technology.

[0004] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0005] A system for connecting an energy storage power station to a power grid, comprising a transformer, an energy storage power station and an access system connecting the energy storage power station and the transformer, wherein the transformer comprises a 1# transformer and a 2# transformer, and the access system comprises a grid cabinet QA0, a grid cabinet QA1 and a grid cabinet QA2, wherein the grid cabinet QA1 is connected to a 10.5 kV busbar of the 1# transformer, the grid cabinet QA2 is connected to a 10.5 kV busbar of the 2# transformer, one end of the grid cabinet QA0 is connected to the grid cabinet QA1 and the grid cabinet QA2, and the other end of the grid cabinet QA0 is connected to the energy storage power station.

[0006] Preferably, a 1# incoming line cabinet is connected between the 1# transformer and the grid-connected cabinet QA1, and a 2# incoming line cabinet is connected between the 2# transformer and the grid-connected cabinet QA2.

[0007] Preferably, a 1# outgoing line cabinet is connected between the 1# incoming line cabinet and the grid-connected cabinet QA1, and a 2# outgoing line cabinet is connected between the 2# incoming line cabinet and the grid-connected cabinet QA2.

[0008] Compared with the prior art, the beneficial effects of the utility model are:

[0009] The utility model connects the energy storage power station to the power grid by using two transformers and three grid-connected cabinets, and controls the charging path of the energy storage power station and the discharging path of the energy storage power station by the 1# transformer and the 2# transformer by comparing the remaining capacity of the 1# main transformer and the 2# main transformer, and the power load on the low-voltage side of the 1# main transformer and the 2# main transformer that can absorb the discharge of the energy storage power station. By charging one transformer and absorbing the discharge of the power load on the low-voltage side of the other transformer, the capacity configuration of the energy storage power station is maximized, thereby further reducing the electricity cost of the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a connection diagram of the utility model energy storage power station connected to the power grid. DETAILED DESCRIPTION

[0011] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below in conjunction with specific implementation methods.

[0012] See also Figure 1 , the utility model provides the following technical solutions:

[0013] A system for connecting an energy storage power station to a power grid comprises a transformer, an energy storage power station and an access system for connecting the energy storage power station and the transformer, wherein the transformer comprises a 1# transformer and a 2# transformer, and the access system comprises a grid cabinet QA0, a grid cabinet QA1 and a grid cabinet QA2, wherein the grid cabinet QA1 is connected to a 10.5 kV busbar of the 1# transformer, the grid cabinet QA2 is connected to a 10.5 kV busbar of the 2# transformer, one end of the grid cabinet QA0 is connected to the grid cabinet QA1 and the grid cabinet QA2, and the other end of the grid cabinet QA0 is connected to the energy storage power station; two transformers and three grid cabinets are used to connect the energy storage power station to the power grid, so as to facilitate charging and discharging of the energy storage power station under different power consumption states, so as to optimize the capacity configuration of the energy storage power station and reduce the electricity consumption cost of the enterprise.

[0014] A 1# incoming line cabinet is connected between the 1# transformer and the grid-connected cabinet QA1, and a 2# incoming line cabinet is connected between the 2# transformer and the grid-connected cabinet QA2. The setting of the incoming line cabinet facilitates the transfer of the transformer busbar; a 1# outgoing line cabinet is connected between the 1# incoming line cabinet and the grid-connected cabinet QA1, and a 2# outgoing line cabinet is connected between the 2# incoming line cabinet and the grid-connected cabinet QA2. The setting of the outgoing line cabinet facilitates the connection of various electrical equipment.

[0015] The specific working process of the energy storage power station connected to the power grid is as follows:

[0016] When the remaining capacity of transformer 1# is greater than the remaining capacity of transformer 2#, and the power load on the low-voltage side of transformer 1# that can absorb the discharge of the energy storage power station is greater than the power load on the low-voltage side of transformer 2# that can absorb the discharge of the energy storage power station, the capacity of the energy storage power station is determined according to the remaining capacity of transformer 1# and the power load. At this time, the energy storage power station is charged through grid cabinets QA1 and QA0, and discharged through grid cabinets QA0 and QA1; the low-voltage side of the transformer is the 10.5kV side.

[0017] When the remaining capacity of transformer 2# is greater than that of transformer 1#, and the power load on the low-voltage side of transformer 2# that can absorb the discharge of the energy storage power station is greater than the power load on the low-voltage side of transformer 1# that can absorb the discharge of the energy storage power station, the capacity of the energy storage power station is determined according to the remaining capacity of transformer 2# and the power load. At this time, the energy storage power station is charged through grid cabinets QA2 and QA0, and discharged through grid cabinets QA0 and QA2.

[0018] When the remaining capacity of transformer 1# is greater than the remaining capacity of transformer 2#, but the power load on the low-voltage side of transformer 1# that can absorb the discharge of the energy storage power station is less than the power load on the low-voltage side of transformer 2# that can absorb the discharge of the energy storage power station, the capacity of the energy storage power station is determined according to the remaining capacity of transformer 1# and the power load on the low-voltage side of transformer 2#. At this time, the energy storage power station is charged through grid cabinets QA1 and QA0, and discharged through grid cabinets QA0 and QA2.

[0019] When the remaining capacity of transformer 2# is greater than the remaining capacity of transformer 1#, but the power load on the low-voltage side of transformer 2# that can absorb the discharge of the energy storage power station is less than the power load on the low-voltage side of transformer 1# that can absorb the discharge of the energy storage power station, the capacity of the energy storage power station is determined according to the remaining capacity of transformer 2# and the power load on the low-voltage side of transformer 1#. At this time, the energy storage power station is charged through grid cabinets QA2 and QA0, and discharged through grid cabinets QA0 and QA1. Under normal circumstances, grid cabinets QA1 and QA2 are not allowed to be closed at the same time, and a chain is set between the two.

[0020] By comparing the remaining capacity of the 1# main transformer and the 2# main transformer, as well as the power load on the low-voltage side of the 1# main transformer and the 2# main transformer that can absorb the discharge of the energy storage power station, the charging path of the 1# transformer and the 2# transformer to the energy storage power station and the discharge path of the energy storage power station are controlled. By charging with one transformer and absorbing the discharge with the power load on the low-voltage side (10.5kV) of the other transformer, the capacity configuration of the energy storage power station is maximized, thereby further reducing the company's electricity costs.

[0021] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A system for connecting an energy storage power station to a power grid, comprising a transformer, an energy storage power station, and an access system connecting the energy storage power station and the transformer, wherein the transformer comprises a 1# transformer and a 2# transformer, and wherein: The access system includes power cabinet QA0, power cabinet QA1 and power cabinet QA2. The power cabinet QA1 is connected to the 10.5kV busbar of transformer #1, the power cabinet QA2 is connected to the 10.5kV busbar of transformer #2, one end of the power cabinet QA0 is connected to the power cabinet QA1 and the power cabinet QA2, and the other end of the power cabinet QA0 is connected to the energy storage power station.

2. A system for connecting an energy storage power station to a power grid according to claim 1, characterized in that: A 1# incoming line cabinet is connected between the 1# transformer and the grid-connected cabinet QA1, and a 2# incoming line cabinet is connected between the 2# transformer and the grid-connected cabinet QA2.

3. A system for connecting an energy storage power station to a power grid according to claim 2, characterized in that: A 1# outgoing line cabinet is connected between the 1# incoming line cabinet and the grid-connected cabinet QA1, and a 2# outgoing line cabinet is connected between the 2# incoming line cabinet and the grid-connected cabinet QA2.

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