2. Energy storage system configured on the AC side of the power supply
The energy storage system configured on the AC side of the power supply can also be called the energy storage system configured on the AC side. Inversion, this solution is actually to attach an energy storage device to the existing photovoltaic power generation system. It can be upgraded and installed in any current photovoltaic power station or even wind power station or other power station to form an in-station energy storage system. The power grid needs to be built into a completely independent energy storage power station.
This mode overcomes the problem that the DC side energy storage system cannot perform unified dispatching of excess power. Its system charging or discharging is completely controlled by the intelligent control system or by the grid dispatching control. It can not only concentrate the excess power in the whole station to the energy storage The fast and effective charging of the system can even dispatch the cheap low-trough excess power of the grid outside the station, making the system operation more convenient and effective. Another mode of the energy storage system connected to the AC side is to connect the energy storage system to the grid. Obviously, the difference between the two energy storage systems is the access point. The former connects the energy storage part to the AC low-voltage side and shares a transformer with the original photovoltaic power station, while the latter forms an independent energy storage system. Power station mode, directly connected to the high-voltage power grid.
The AC side access scheme is not only suitable for grid energy storage, but also widely used in relatively isolated areas such as islands to form a relatively independent micro-grid power supply system. The energy storage system connected to the AC side can not only be implemented in newly built power stations, but also can be easily transformed and additionally constructed for already built power stations. The circuit structure is clear, and the power generation field and the energy storage field can be constructed separately. There are few direct correlations, so it is also easy to operate control and maintenance. The disadvantage is that since power generation and energy storage are independent of each other, the coordination and control of each other requires an additional set of special intelligent control and dispatch system, so the cost is relatively high.
3. Configure the energy storage system on the load side
The energy storage system configured on the load side mainly refers to emergency power supply and movable electric equipment, such as rechargeable electric vehicles, electric tools and mobile phones.
This article only discusses the technical issues of energy storage power stations. Although energy storage power stations have many advantages, they can be implemented and applied in some special occasions. However, due to the current key issues such as high efficiency, environmental protection, long life and low price of batteries, there is no major breakthrough. In the current large-scale promotion of energy storage power stations, there may be issues such as on-grid electricity prices and subsidy policies.