Application Analysis of Energy Storage System Based on Supercapacitor in Distributed Microgrid

With the development of renewable energy power generation technology, microgrids capable of integrating distributed power sources are an effective way to meet increasing power demand, save investment and improve energy efficiency. As an energy buffering part of the microgrid, the Energy Storage System plays an increasingly important role. The characteristics and performance of supercapacitors are summarized. The structure and control principle of supercapacitor Energy Storage system are analyzed, and its application in microgrid is elaborated. The supercapacitor-based energy storage system not only functions as an energy buffer, but also provides short-time power supply, buffers load fluctuations in the microgrid, equalizes micro-power output, improves microgrid power quality, and is important for the economic performance of the microgrid, effect.

Today's society has higher and higher requirements for the quality and safety and reliability of energy and power supply. The traditional large-grid power supply method cannot meet this requirement because of its own defects. A new type of power grid that can integrate distributed power generation – microgrid emerges as the times require. It can save investment, reduce energy consumption, improve system security and flexibility, and is the future development direction. As an indispensable energy storage system in the microgrid, it plays a very important role. As a new type of energy storage device, supercapacitor is one of the preferred devices for microgrid energy storage because of its irreplaceable superiority.

At present, in the relatively remote mountainous areas of China, the cost of erecting transmission lines is relatively high, and even if the transmission lines are erected, the operating costs are high, so it is difficult to achieve electrification. If wind power or solar power is used to build a microgrid, the electric field that converts electricity into a supercapacitor can be stored. It is very economical to convert the electric field energy into electrical energy when needed, without any damage to the environment.

For most rural areas in China, the reliability of the power grid is often not high, and short-term power outages are inevitable. However, the cost of improving reliability is too high. The microgrid can be built up in the load concentration area, and the power is stored by the supercapacitor energy storage system when the power is normally supplied, and is supplied by the supercapacitor energy storage system during the power outage. Even in China's more developed urban areas, supercapacitor energy storage systems play an important role. The supercapacitor energy storage system stores the power when the power is sufficient, and feeds back to the grid when the power supply is insufficient, ensuring that the grid load is always balanced. At the same time, the supercapacitor energy storage system can improve the power quality, replace the currently used UPS, and improve the reliability of power supply for important load devices such as communication devices, computers and medical equipment.

It can be seen that the ultra-capacitor energy storage system which is economical and Environmentally Friendly has great market prospects. The application of the supercapacitor energy storage system in the microgrid also meets the requirements for environmental protection. Non-polluting energy sources such as solar energy, wind energy and fuel cells are stored in supercapacitors, providing electricity in a timely manner. There is no need to invest in large power stations or complex transmission networks. It is a kind of investment that can effectively use renewable energy. Energy saving measures.

Characteristics of supercapacitors:

Supercapacitor, also known as Electrical Double-Layer Capacitor, Gold Capacitor, Farad Capacitor, is a new type of energy storage component between traditional capacitors and rechargeable batteries, with a capacity of several hundred to tens of thousands. The method has a specific power of more than 10 times that of the battery, and has a higher storage capacity than ordinary capacitors. It has a wide operating temperature range, rapid charge and discharge, long cycle life, no pollution, and zero emissions.

1) Has an extremely high capacity. The capacity of supercapacitors can be up to 10,000 FF, which is 2000-6000 times larger than the capacity of electrolytic capacitors of the same volume.

2) Has a very high power density. Supercapacitors have a power density of around 18 kW/kg and can discharge hundreds to thousands of amps in a short period of time. This feature makes supercapacitors ideal for short-term, high-power output applications.

3) The charging and discharging speed is fast. Supercapacitors do not produce a chemical reaction and can store electricity directly. The time required for charging is very short. Supercapacitor charging can be charged with a large current, and the charging process can be completed in several tens of seconds to several minutes, which is a true fast charging. The battery takes a few hours to complete the charging, and it takes dozens of minutes to use the fast charging.