Gigwatt-level electrochemical energy storage station and station power utilization system

Abstract

The utility model discloses a gigawatt-level electrochemical energy storage station and a station power utilization system, which comprise a dual-power switching device, a three-split transformer, an isolation transformer, a grounding transformation and booster station transformer and an alternating current screen, wherein the three-split transformer is adopted as the booster transformer of an electrochemical energy storage unit of two sections of buses; wherein one low-voltage side winding is connected with an energy storage converter and a lithium iron phosphate battery pack, the other low-voltage side winding is connected with a bus of an alternating current screen through an isolation transformer and a dual-power-supply switching device in a crossed mode and is in mutual hot standby, and two sections of buses of different main transformers are connected with two sections of buses of 380V through two grounding transformers and booster station transformers. An external 10kV line is connected with a zero-section bus of 380V through a standby transformer, original four station transformers are canceled, and an isolation transformer is additionally arranged, so that the construction cost is saved; 380V sides of the isolation transformers of different 35kV bus sections are in cross connection through the dual-power switching device, so that the reliability of power supply is ensured.

Description

Technical Field

[0001] The utility model belongs to the field of electrochemical energy storage, in particular to a type applicable to a gigawatt-level electrochemical energy storage station and a station service power system. Background Technique

[0002] In the hotspots for the development of renewable energy such as photovoltaic and wind power, large-scale renewable energy bases have been planned at the sending end of UHV DC projects. The capacity of grid-side energy storage power stations is mostly 10MW / 20MWh to 100MW / 200MWh. Although certain experience has been accumulated in the design of these energy storage power stations, due to factors such as the rapid development of energy storage technologies and the lack of industry standards and design standards, the construction of gigawatt-level (500MW / 1GWh) grid-side energy storage power stations still faces many difficulties. A gigawatt-level energy storage power station can be defined as: within the same regional power grid, the centralized or distributed electrochemical energy storage capacity that can be uniformly dispatched by the power grid reaches the gigawatt level. Therefore, there is an urgent need for large-capacity gigawatt-level (500MW / 1GWh) energy storage power stations, which is also an inevitable choice for technological iteration. Currently, although certain experience has been accumulated in the design of energy storage power stations, due to factors such as the rapid development of energy storage technologies and the lack of industry standards and design standards, the construction of gigawatt-level (500MW / 1GWh) grid-side energy storage power stations still faces many difficulties.

[0003] In the prior art, the station service power system of an electrochemical energy storage station includes 4 sets of 38.5 / 0.4kV 3500kVA station service transformers, 2 sets of 38.5 / 0.4kV 800kVA station service transformers, 1 set of 10 / 0.4kV 800kVA station service transformer, and 4 sets of 38.5kV 1250kVA grounding transformers, as Figure 1 shown. Among them, the 35kV I, II, III, and IV busbars are respectively stepped down to 0.4kV through 4 sets of 38.5 / 0.4kVA 3500kVA station service transformers, and then connected through bus coupler switches and then connected to the station service AC panel of the energy storage station for power supply; the 35kV I, II, III, and IV busbars also need to be grounded through the neutral points of 4 sets of 38.5kV 1250kVA grounding transformers; the 35kV II and IV busbars also need to supply power to the AC panel in the boosting area of the energy storage station through 2 sets of 38.5kV 800kVA station service transformers and 1 set of 10kV 800kVA station service transformer.

[0004] The GW-level energy storage station is huge in scale. Once there are problems with the station power supply system, it will directly or indirectly affect the safe and reliable operation of the energy storage batteries in the energy storage power station. In severe cases, it may even lead to malignant accidents such as battery fires, and the severity of the consequences will be more than several times that of MW / MW-level energy storage power stations. Therefore, there are extremely high requirements for the reliability of power supply. The site structure of the GW-level energy storage station has two possibilities: centralized and distributed layouts. However, whether it is a centralized or distributed layout, the site occupies a large area, and the station loads are relatively scattered throughout the site. Its layout and control are both multi-level and decentralized, and microgrid technology needs to be adopted; the environmental temperature has a very large impact on the performance of the batteries. Therefore, the station power load of the energy storage power station mainly comes from the cooling load during the charge and discharge process of the energy storage batteries. When the scale of the energy storage station reaches the GW level, its station power load will also reach the MW level. The electrochemical battery pack itself is a power source, and the station power supply system needs to be organically integrated with the chemical battery pack system, new energy sources such as wind and light to reduce the plant power consumption rate.

[0005] The existing power supply systems of energy storage stations have the following deficiencies:

[0006] 1. There are many station transformers, and the purchase price is high, resulting in a relatively high investment in the station power supply of the GW-level energy storage station.

[0007] 2. The environmental temperature has a very large impact on the performance of the electrochemical batteries used in the GW-level electrochemical energy storage station. Its station power load mainly comes from the cooling load during the charge and discharge process of the electrochemical batteries. There are many station transformers, the equipment utilization rate is not high, and the power grid loss rate of the station power supply is high.

[0008] 3. The station power supply of the energy storage station is taken from the 330 kV main transformer. Once the main transformer is under maintenance or fails, there will be an AC power outage, and only a small number of important loads can be powered by the battery pack, so the power supply reliability is not high. Summary of the Utility Model

[0009] The purpose of the present utility model is to overcome the above-mentioned deficiencies of the existing technologies and provide a station power supply system for a GW-level electrochemical energy storage station.

[0010] The purpose of the present utility model is realized by adopting the following technical solutions: A station power supply system for a GW-level energy storage station includes a dual-power switching device, a three-split transformer, an isolation transformer, a grounding transformer and a step-up station transformer, and an AC panel. The step-up transformers of the electrochemical energy storage units on two busbars adopt three-split transformers. One low-voltage side winding is connected to the energy storage converter and the lithium iron phosphate battery pack, and the other low-voltage side winding is cross-connected to the busbar of the AC panel through the isolation transformer and the dual-power switching device, being in hot standby with each other. The two busbars of different main transformers are connected to the two 380V busbars through two grounding transformers and step-up station transformers, and an external 10 kV line is connected to the 0-section busbar of 380V through a standby transformer.

[0011] Furthermore, both sections of the busbars are 35 kV, and the three - split transformer is 38.5 / 0.69 / 0.69 kV 3500 / 1750 / 1750 kVA. Among them, the main winding transformer uses 38.5 kV, and the low - voltage side winding is 0.69 kV.

[0012] Furthermore, the dual - power - supply switching device is directly connected to the AC load, and the dual - power - supply switching device is connected to the DC load through an inverter.

[0013] Furthermore, the grounding transformer and the step - up transformer for the substation are 38.5 / 0.4 kV, the isolation transformer is 0.69 / 0.38 kV, and the standby transformer is 10 / 0.4 kV.

[0014] Furthermore, the output ends of the four isolation transformers are cross - connected with the dual - power - supply switching device in pairs. The output end of the dual - power - supply switching device is connected to the busbars of the 0.38 kV AC panel, and they are in hot standby with each other.

[0015] Furthermore, the input ends of the two grounding transformers and step - up transformers for the substation are connected to two sections of 35 kV busbars of different main transformers.

[0016] Furthermore, both sections of the 380 V busbars are connected to the AC load and are connected to the DC load through an inverter.

[0017] Furthermore, the 0 - section, 1 - section, and 2 - section busbars of 380 V are connected through the bus - tie switch.

[0018] At the same time, an energy storage station is provided, which adopts the station - use power system of the above - mentioned GW - level energy storage station.

[0019] Furthermore, the energy storage station is a 500 MW / 1000 MWh energy storage power station or a shared energy storage station.

[0020] Compared with the prior art, the present utility model has the following beneficial effects: The original four 38.5 / 0.4 kVA 3500 kVA station - use transformers are cancelled. The step - up transformer of the electrochemical energy storage unit uses a three - split transformer, and an isolation transformer is added. The cost of the isolation transformer is much lower than that of the original station - use transformer, saving the project cost. The 380 V sides of the isolation transformers of different 35 kV busbar sections are cross - connected through the dual - power - supply switching device to ensure the reliability of power supply; The two 38.5 / 0.4 kV 800 kVA station - use transformers and the two 38.5 kV 1250 kVA grounding transformers are combined into two grounding transformers and station - use transformers, improving the utilization efficiency of the station - use transformer and reducing the station - use power rate. The 380 V 0 - section, 1 - section, and 2 - section busbars of the two 38.5 / 0.4 kV grounding transformers and station - use transformers connected to different 35 kV busbar sections and the 380 V 0 - section, 1 - section, and 2 - section busbars of a station standby transformer connected from an external power source are connected through the bus - tie switch, improving the reliability of power supply.

[0021] In summary, the present invention provides a station power system for a gigawatt-level electrochemical energy storage station, using the secondary winding of the three-split transformer of the electrochemical energy storage module as the station transformer, achieving the following technical effects: 1. The original four station transformers are eliminated and an isolation transformer is added. The cost of the isolation transformer is much lower than that of the original station transformer, saving engineering costs. 2. The 380V sides of the isolation transformers of different 35kV busbar sections are cross-connected through a dual power switching device to ensure the reliability of power supply. 3. The station transformer and the grounding transformer are merged into a grounding transformer and station transformer, which improves the utilization efficiency of the station transformer and reduces the station power consumption rate.

[0022] Furthermore, the grounding transformer and station transformer is connected to a station transformer connected to the power supply outside the station through a busbar switch to improve power supply reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the power system structure of the electrochemical energy storage station in the prior art of the present utility model background technology

[0024] Figure 2 It is a schematic structural diagram of the power supply system of the gigawatt-class energy storage station using electrochemical energy storage units according to the present invention. DETAILED DESCRIPTION

[0025] In order to help those skilled in the art better understand the present invention, 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 embodiments described 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 making creative efforts should fall within the scope of protection of the present invention.

[0026] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0027] This application analyzes the load in the step-up substation area of the grid-side GW-level energy storage power station: The station service loads in the step-up substation area mainly include the main transformer air-cooling load, the distribution device operation load, the lighting load, the HVAC load, the communication power supply load, the maintenance power supply load, the pump load, etc., which are basically the same as the load types of conventional substations.

[0028] 1) Distribution device operation load. The distribution device operation load is responsible for supplying power to the operating structure of the switchgear and providing the energy required for opening and closing. It belongs to the frequently and intermittently operating load. To calculate the maximum load required for the operation of the switchgear, consider the maximum number of circuit breakers that operate simultaneously under extreme conditions. For the 330 kV, a 3 / 2 wiring is adopted. Considering a fault on one 330 kV bus, and at the same time, due to the refusal of the main transformer incoming line circuit breaker connected to this bus to operate, at this time, the intermediate circuit breaker of the 330 kV incoming line through the string of this main transformer needs to trip, and the 330 kV main transformer incoming line circuit breaker on the opposite side of this main transformer also needs to trip. Then, a total of 8 330 kV circuit breakers need to operate. The operation load of a single circuit breaker is 8 kW, the motor load of the 330 kV I bus PT intelligent control cabinet is at most 15 kW, and the total required load is 79 kW.

[0029] 2) Lighting load. Since in the step-up substation area of the energy storage station, the indoor lamps generally will not all be turned on simultaneously. When calculating the total station service load, consider the lighting that works simultaneously, and multiply the total lighting load by a certain correction factor.

[0030] 3) HVAC load. The HVAC load mainly refers to supplying power to the air conditioners, fans, etc. in the station to adjust the indoor temperature and ensure the air circulation. In the unattended mode, this load mainly ensures the normal operation of the secondary equipment and belongs to the frequently and continuously operating load. The electric heater load in each building is 16 kW.

[0031] 4) Other loads. Other loads include the distribution device heating load, the maintenance power supply, the communication power supply, the UPS power supply, the charger, the AC distribution panel, the inverter, the rainwater pump, etc. The distribution device heating power supply is responsible for supplying power to the heating devices of the terminal box and the control cabinet. When the temperature is too low, it maintains the power supply of the heating devices in the terminal box and the control cabinet, and keeps the temperature in the terminal box and the control cabinet to ensure the normal operation of the secondary equipment. It belongs to the frequently and continuously operating load. Then, a total of 9 330 kV circuit breaker control cabinets need to be heated. The heating power of a single circuit breaker control cabinet is 10 W, and there are 2 bus intelligent component cabinets, with a single bus intelligent component cabinet being 5 kW. The total required load is 100 kW. The maintenance power supply is responsible for supplying power to maintenance equipment such as welding machines during equipment maintenance and belongs to the infrequently and short-term operating load, which is not included in the total station service load statistics. The communication power supply, the UPS power supply, the charger, the inverter, etc. belong to the load requirements of the communication and secondary specialties and are frequently and continuously operating loads of 25 kW.

[0032] Load analysis of the energy storage station area of the grid-side GW-level energy storage power station:

[0033] The loads in the energy storage area mainly include the loads of the battery cabin air conditioner and liquid cooling equipment, and the loads of the integrated cabin of PSC and step-up transformer. The magnitude of this load mainly depends on the type of battery, the cooling method and the quantity.

[0034] (1) Type of battery. At present, the main technical route of energy storage power stations in China is lithium iron phosphate batteries. Therefore, mature and reliable lithium iron phosphate batteries are the first choice for GW-level energy storage stations. (2) The optimal temperature range, operating temperature range and tolerable temperature range of lithium iron phosphate batteries are 10 - 35 °C, -20 - 45 °C and -40 °C - 60 °C respectively. The electrochemical characteristics of lithium ions are the best in the temperature range of 10 - 35 °C. Lithium iron phosphate batteries should be operated in this temperature range as much as possible. The life attenuation of lithium-ion batteries is small within -20 - 45 °C and they can still operate normally. However, when the temperature is within -20 - -40 °C, the electrolyte may solidify, hindering the flow of lithium ions, resulting in an increase in impedance and a significant decrease in battery capacity. When the temperature exceeds 60 °C, the chemical characteristics of lithium ions begin to become increasingly unstable, the rate of harmful chemical reactions inside the battery is high, which may damage the battery and even cause accidents in severe cases. To keep the operating temperature of lithium iron phosphate batteries within the safe range, methods such as air cooling or liquid cooling are needed to cool the cabin. In cold seasons and regions, air conditioners, coils or electric heating are needed to heat and insulate the battery cabin.

[0035] According to the AC load in the step-up station area of the GW-level energy storage station and the AC load in the energy storage area of the GW-level energy storage station, the AC power consumption load in the step-up station area is about 800 kVA. Considering a certain margin, a 35 kV 1000 kVA station service transformer is selected. The AC power consumption load in the energy storage area is 3765 kVA. Considering a certain margin, a 35 kV 4000 kVA is selected.

[0036] According to the regulations of relevant design codes for electrochemical energy storage power stations, the GW-level energy storage power station consists of 8 station service transformers, among which 4 are 35 kV grounding transformers and also station service transformers with a capacity of 800 kVA, respectively taken from the 35 kV section I and section II of different step-up station main transformers. Another 4 35 kV station service transformers with a capacity of 4000 kVA are respectively taken from the 35 kV section I and section II of different step-up station main transformers. In addition, a 35 kV or 10 kV off-site power source is introduced from outside the 35 kV as a standby power source. There are two power supply methods for the GW-level energy storage power station on the grid side: (1) Adopt the loop power supply method and set knife switches at intervals in the ring network to operate in an open-loop manner. (2) Adopt the radial power supply, and special distribution boxes are set for each configured electrical installation site. One of the power supply inlets of the distribution box operates and the other is in standby.

[0037] For the application scenarios of GW-level energy storage power stations with high reliability, large floor area, and large station load, since the AC load of GW-level energy storage power stations is mainly the cooling load of battery cabins, there are more than 400 battery cabins, and they are under the same environmental conditions and have the same input load. Therefore, the upper-layer radiation and lower-layer ring power supply schemes are excluded. The application scenarios of GW-level energy storage power stations have a large floor area, and the station's AC load reaches 4000 kVA. Although the ring network saves the length of cables, to ensure the sensitivity of the circuit breaker at the end of the ring power supply network during a short circuit, it is necessary to increase the cable cross-section, and the cable laying construction is extremely inconvenient. Therefore, the upper-layer ring network and lower-layer radiation power supply method are not suitable. The application scenarios of GW-level energy storage power stations have a large floor area, and there are more than 400 battery cabins. If the double-layer radiation - small room setting with a dedicated distribution panel scheme is adopted, the number of AC circuits in the small rooms only for the energy storage area is initially estimated to reach more than 800. Even calculated according to 24 circuits of the fixed distribution panel, 34 AC distribution panels are required only for the energy storage area. At the same time, since all cables are led from the relay room to the battery cabins, there are many large-section cables and long small-section cables. Overall, the total cable kilometers of the whole station increase; at the same time, the distribution panels in the room will occupy the space of the relay room and increase the area of the relay room. Therefore, the double-layer radiation - small room setting with a dedicated distribution panel scheme is excluded. Based on the double-layer load - local setting of a dedicated distribution box, this application proposes to disperse and arrange AC prefabricated cabins in different areas of the energy storage station, and the power consumption of the power distribution device can be led out from the AC prefabricated cabins; as an example, a 500MW / 1000MWh-level energy storage station consists of 400 sets of 2.56MWh battery cabins + 2.5MW PCS cabins, and can be divided into 4 areas according to 100MW / 1000WMh, and 4 AC cabins are set respectively. Each AC cabin takes one circuit from each of the station's I and II sections of the service power supply as a backup AC power supply. Each AC cabin is equipped with 10 AC panels, which supply power to the battery cabins, PCS, and converter cabins through 2 circuits respectively. Since the radial power supply is adopted, the power supply reliability is high. By setting AC cabins in different areas, the cable cross-section and length from the AC cabins to the battery cabins can be reduced while ensuring sensitivity. At the same time, although the AC panels are placed in the cabins and the upfront investment in the project is relatively large, due to the improvement of the working environment of the AC panels, the cost is more favorable over the entire life cycle.

[0038] The AC-DC hybrid microgrid is also a type of AC microgrid, and its general structure model is that the power grid is connected to the AC bus and is connected to the DC bus through the main inverter. The AC-DC system well integrates the advantages of DC microgrids and AC microgrids. Considering the application scenarios of energy storage power stations with both AC loads and DC loads, the station service AC-DC microgrid scheme can be adopted.

[0039] The following further describes the present utility model in detail with reference to the accompanying drawings:

[0040] Please refer to Figure 1, A station power supply system for a GW-level energy storage station, including a dual-power switching device, a three-split transformer, an isolation transformer, a grounding transformer and step-up station service transformer, and an AC panel. The key points of its system architecture are as follows: The step-up transformers of 4 electrochemical energy storage units adopt a three-split transformer 38.5 / 0.69 / 0.69 kV 3500 / 1750 / 1750 kVA. Among them, the 38.5 kV main winding transformer is connected to the 35 kV I, II, III, and IV busbars through 35 kV cables. One of the 0.69 kV low-voltage side windings is connected to the energy storage converter and the lithium iron phosphate battery pack through a 0.75 kV cable. The other 0.69 kV low-voltage side winding is connected to the input end of a 0.69 / 0.38 kV isolation transformer through a 0.75 kV cable.

[0041] The output ends of 4 0.69 / 0.38 kV isolation transformers are cross-connected to the dual-power switching device in pairs through 0.6 / 1 kV cables. The output end of the dual-power switching device is connected to the busbar of the 0.38 kV AC panel through a cable, and they are in hot standby with each other.

[0042] The input ends of two 38.5 / 0.4 kV grounding transformers and step-up station service transformers are connected to two sections of 35 kV busbars of different main transformers, and the output ends are connected to two sections of 380 V busbars. One 10 kV line is introduced from outside the station and connected to the 0 section busbar of 380 V through a 10 / 0.4 kV standby transformer. The 0, 1, and 2 section busbars of 380 V are connected through the bus-tie switch.

[0043] The solution described in this application is used in the engineering practice of a 500 MW / 1000 MWh energy storage power station or a shared energy storage power station of a certain new energy company. The construction scale of the energy storage power station is 500 MW / 1000 MWh and it is connected to the grid at a voltage level of 330 kV. It is planned to use a single 330 kV line to access the 330 kV AC distribution device of a 750 kV substation. After the project is connected to the grid and generates electricity, each single charge can store up to 300,000 kWh of green electric energy. By using the energy storage's "peak shaving and valley filling" adjustment ability, it can realize off-peak storage and release of green electricity, promote the realization of "24-hour green electricity supply", solve more than 79 million kWh of abandoned new energy electricity, reduce the system coal consumption by about more than 60,000 tons, and will play a positive role in promoting the consumption of new energy in this region, reducing the grid load pressure, and assisting in energy supply guarantee.

[0044] According to the system plan, a 330 kV step-up substation needs to be built to meet the voltage levels of 330 kV / 35 kV. The total capacity of the main transformers in the long-term plan is 1 unit of 240 MVA and 1 unit of 360 MVA, meeting the grid connection requirements of the energy storage power station with an installed capacity of 500 MW / 1000 MWh. The transformer-line unit wiring is built on the 330 kV side in this phase. The 35 kV main wiring of each main transformer adopts a single-bus double-branch wiring. Two sections of 35 kV busbars need to be built in this phase. The 35 kV busbars are planned to have 19 outgoing lines, and each section of the 35 kV busbar has 3 / 3 outgoing lines in this phase.

[0045] The energy storage adopts a lithium iron phosphate battery energy storage system, which consists of 150 container energy storage systems with a capacity of 3.45MW / 6.7MWh. The distributed prefabricated cabins are installed outdoors at the planned site. The energy storage system uses 4 sets of 38.5kV / 0.69kV / 0.69kV split transformers as the basic access units. After the 38.5kV sides of the split transformers are collected through 35kV collector lines, they are connected to the 35kV low-voltage side busbar of the 330kV energy storage booster station to realize the integration of the energy storage system and grid connection. One low-voltage 0.69kV side winding of the split transformer is connected to the energy storage converter and the lithium iron phosphate battery pack, and the other low-voltage 0.69kV side winding is cross-connected to the busbar of the AC panel through a 0.69 / 0.38kV isolation transformer and a dual-power switching device, serving as a hot standby for each other. The two busbars of different main transformers are connected to the two 380V busbars through two 38.5 / 0.4kV earthing transformers also used as booster station transformers. An external 10kV line is connected to the 0-section busbar of 380V through a 10 / 0.4 kV standby transformer. Further, the input ends of the two earthing transformers also used as booster station transformers are connected to the two 35kV busbars of different main transformers. The two 380V busbars are both connected to AC loads and DC loads through converters, and the 0-section, 1-section, and 2-section busbars of 380V are connected through a bus-tie switch.

[0046] Through the system described in the present utility model, 8 sets of 38.5kV / 0.4kV station transformers are changed to 4 sets of 38.5kV / 0.69kV / 0.69kV split transformers, reducing line losses and saving about 1.2 million yuan in project cost. By adopting a cross-connected power supply method, the power supply reliability of the extra-large energy storage power station is improved at the same time.

[0047] The above content is only to illustrate the technical idea of the present utility model, and the protection scope of the present utility model cannot be limited thereby. Any modification made on the basis of the technical solution according to the technical idea proposed by the present utility model falls within the protection scope of the claims of the present utility model.

Claims

1. A station power supply system for a multi-GW electrochemical energy storage station, characterized in that It includes a dual-power switching device, a three-phase-split transformer, an isolation transformer, a grounding transformer and a step-up transformer for the booster station, and an AC panel. The step-up transformers of the electrochemical energy storage units on the two busbars adopt three-phase-split transformers. One of the low-voltage side windings is connected to the energy storage converter and the lithium iron phosphate battery pack, and the other low-voltage side winding is cross-connected to the busbar of the AC panel through the isolation transformer and the dual-power switching device, being in hot standby with each other. The two busbars of different main transformers are connected to the two 380V busbars through two grounding transformers and step-up transformers for the booster station, and an external 10kV line is connected to the 0th section busbar of 380V through a standby transformer.

2. The station power supply system of the multi-GW electrochemical energy storage station according to claim 1, characterized in that Both of the two busbars are 35kV, and the three-phase-split transformer is 38.5 / 0.69 / 0.69kV 3500 / 1750 / 1750kVA, where the main winding transformer uses 38.5kV and the low-voltage side winding is 0.69kV.

3. The station power supply system of the multi-GW electrochemical energy storage station according to claim 1, wherein The dual-power switching device is directly connected to the AC load, and the dual-power switching device is connected to the DC load through a converter.

4. The station power supply system of the GW-level electrochemical energy storage station according to claim 1, characterized in that The grounding transformer and step-up transformer for the booster station is 38.5 / 0.4kV, the isolation transformer is 0.69 / 0.38kV, and the standby transformer is 10 / 0.4 kV.

5. The station power supply system of the multi-GW electrochemical energy storage station according to claim 1, wherein The output terminals of the four isolation transformers are cross-connected to the dual-power switching device in pairs, and the output terminals of the dual-power switching device are connected to the busbar of the 0.38kV AC panel, being in hot standby with each other.

6. The station power supply system of the GW-level electrochemical energy storage station according to claim 1, characterized in that, The input terminals of the two grounding transformers and step-up transformers for the booster station are connected to the two 35kV busbars of different main transformers.

7. The station power supply system of the GW-level electrochemical energy storage station according to claim 1, wherein, Both of the two 380V busbars are connected to the AC load and are connected to the DC load through a converter.

8. The station power supply system of the multi-GW electrochemical energy storage station according to claim 1, characterized in that, The 0th section, 1st section and 2nd section busbars of 380V are connected through a bus-tie switch.

9. A energy storage station, characterized in that, Adopt the station service power system of the GW-level electrochemical energy storage station described in any one of claims 1-8.

10. The energy storage station according to claim 9, wherein It is a 500MW / 1000MWh energy storage power station or a shared energy storage power station.

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