I. Working Principle of Superconducting Energy Storage System
Its working principle is as follows: During normal operation, the grid current charges the superconducting inductor through rectification, and then maintains constant current operation (due to the use of superconducting coils for energy storage, the stored energy can be stored permanently with almost no loss until it needs to be released). When the grid experiences transient voltage drops or surges, or transient active power imbalances, energy can be extracted from the superconducting inductor, converted into AC by an inverter, and output to the grid with flexibly adjustable active or reactive power, thereby ensuring the stability of the grid's transient voltage and active power balance.
II. Applications of Superconducting Energy Storage Systems
1. It can be used to eliminate low-frequency oscillations in power systems and to stabilize the frequency and voltage of the system.
2. It can be used for reactive power control and power factor adjustment to improve the stability and power transmission capacity of the power transmission system.
3. Because it can rapidly add or absorb active power to the grid, a system with a superconducting energy storage device can be considered a flexible AC transmission system.
4. If it is considered not only as an energy storage device, but also as an active power source for system operation and control, it will be more useful and effective, and therefore can be used as a superconducting energy management system.
5. The AGC system has an automatic power generation control function, and local control errors can be minimized.
6. It can be used in power distribution systems or large load sides to reduce fluctuations and balance peak loads, control primary power and improve transient stability, and can achieve good results.
7. It can be used in island power supply systems. Because the cost of connecting islands to the mainland is high, gas turbines are generally used to generate electricity independently and connect to the grid. Superconducting energy storage devices can be used for load regulation, etc.
8. It can be used to compensate for fluctuating loads such as those from starting large electric motors, welding machines, electric arc furnaces, sledgehammers, and rolling mills, thereby reducing the flickering of lights on the power grid.
9. It can also be used for energy storage in solar and wind power fields. Wind power generation will produce pulsating power output and bring many problems to the distribution network, while superconducting energy storage devices can smooth the output of wind power generation systems to meet the requirements of the distribution network, and provide backup power and control frequency for the system.
10. It can be used as an energy storage device for other distributed power systems.
11. It can be used as an uninterruptible power supply to provide high-quality power to important loads and limit short-circuit current when a short circuit occurs on the load side.
