The battery energy storage station does not have special requirements on geographical conditions like pumped storage stations and compressed air energy storage stations. It has strong geographic adaptability and has a small area. In large-capacity projects, more energy storage stations can be used. Layered three-dimensional design to save floor space. So it can be widely used in urban power distribution network, user side, new energy power generation side and electric car charging station.
①Apply to distribution network substation
The power grid company alone invests in construction and operation scheduling. On the one hand, the power grid company can use its low storage and high power generation to achieve peak-shaving and valley-filling, relieve the power supply pressure of the power grid during peak load, delay the expansion of distribution network capacity, and increase the utilization rate of distribution network equipment. Reduce the cost of power grid operation. At the same time, because more low-priced electricity is purchased during peak hours, the high-priced electricity that the grid needs to buy during peak hours is reduced, thereby reducing the power purchase cost of the grid company. Energy storage stations can provide auxiliary services such as frequency modulation, reactive power support, and backup, which can reduce the auxiliary service fees that grid companies need to pay. On the other hand, energy storage stations can quickly adjust active and reactive power, which can improve power quality. At the same time, they can perform voltage control and power flow management in response to most faults in the distribution network, thereby improving the safety of the distribution network. Operational performance. Because the capacity used for peak shaving needs to be relatively large to have a more obvious effect, and lead-acid batteries are poor in environmental protection and have been gradually eliminated. Therefore, it is advisable to use energy storage technology with large specific capacity such as sodium-sulfur battery.
②Apply to the user side
For large users with high power supply reliability requirements and large load peak-to-valley differences, storage batteries can be used to improve power supply reliability. For example, large hospitals have very high requirements for power supply reliability. Battery energy storage can be used as a UPS to quickly transfer to the power storage station power supply state at a millisecond switching speed when power supply fails to ensure uninterrupted power supply for electrical equipment. In some high-tech enterprises, a power outage of one-tenth of a second will result in a large number of product scraps, with losses of up to tens of millions of yuan. The storage battery can ensure the continuity of production and power supply. At the same time, after large users install battery energy storage stations, they can reduce the redundancy of the power distribution system to improve the reliability of power supply, save capacity investment, and under the two-part electricity price, the power distribution capacity is reduced, and the monthly payment is required The cost of capacity has also been reduced, which can reduce the cost of capacity electricity on one side, and on the other hand, reduce the cost of electricity purchase by purchasing more low-priced electricity and reducing the number of high-priced electricity purchases.
③Apply to large-scale new energy power generation
At present, large-scale new energy power generation is mainly wind power and solar power. Generally, it is connected to the distribution network. When the scale of wind power reaches the capacity limit of the distribution network, it will cause the safety of grid operation. At the same time, when wind power peaks are mostly at night load valleys, the grid capacity will be further reduced, and wind will have to be abandoned. The construction of battery energy storage stations in wind farms can store surplus wind power at night to achieve day and night peak shaving and filling. At the same time, it can effectively improve the quality of wind power, and reliably solve the problem of low voltage ride through and reactive power compensation. It can not only increase the power generation of the wind farm, increase the benefits of the wind farm, but also improve the operation of the wind farm and reduce the supply of wind power to the grid. Risks brought by operation. From the perspective of the development of energy storage technology abroad, the operation mode of wind farm combined with vanadium battery energy storage system is mostly adopted.
At the same time, distributed power generation is gradually emerging, which puts forward higher requirements for load-side operation control of the distribution network. By adopting battery energy storage technology, it can have the following effects on distributed power generation, so as to ensure that the system remains under the impact of distributed power generation. Safe and reliable operation:
1) Improve power quality and maintain system stability. In wind power generation, the change of wind speed will change the output mechanical power of the prime mover, so that the output power of the generator will fluctuate and the power quality will be reduced. The application of energy storage devices is an effective way to improve the output voltage and frequency quality of generators, and at the same time increase the reliability of distributed generator sets when they are connected to the grid. The combination of reliable distributed power generation units and energy storage devices is one of the effective means to solve dynamic power quality problems such as voltage drops, inrush currents and instantaneous power supply interruptions.
2) Provide electricity to users when the distributed power generation device fails to work normally. In some special cases, such as solar power at night and wind power without wind, the energy storage device can play a transitional role and continue to supply power to users.
3) Improve the economic benefits of the owners of distributed power generation units. In the environment of the electricity market, distributed power generation units and the grid become dispatchable unit units. Power generation unit owners can sell electricity to power companies according to different situations, provide peak shaving and emergency power support services, and obtain maximum economic benefits.
④Apply to electric car charging station
Different from small chargers in garages, electric car charging stations mostly use fast high-current charging with a short duration of 10~15mim. The maximum power of a single large charger is 200kW, and the maximum power of a single medium charger is 100kW. Therefore, the load of the charging station presents the characteristics of intermittent pulse load. Due to the large instantaneous power, the impact on the grid is great, and the charging peak of the charging station is mostly during the peak load period during the day, so it brings a series of challenges to the operation of the grid . If the charging station is equipped with a certain scale of battery energy storage, from an economic point of view, on the one hand, the power transformation, rectification and filtering equipment of the shared charger can be used to greatly reduce the investment in the energy storage device; on the other hand, the battery can be used It stores electric energy during the valley load period and is used for charging electric cars during peak charging periods, reducing the cost of electricity purchase at charging stations, and at the same time providing battery replacement services for charging stations. From the perspective of grid operation, battery energy storage can greatly reduce the impact of the charging station load on the grid during the peak charging period, and relieve the power supply pressure of the grid during the peak load. Considering that the charging station provides battery replacement services and the electric vehicle power battery has the characteristics of large current, the energy storage battery in the charging station should use nickel-metal hydride batteries and lithium batteries with a larger output current.
