| Among several reactive power compensation devices applied in power system, STATCOM possesses distinguishing features of small,fast response, wide operation range and low operational loss. Besides, it can reduce the harmonic content of the compensation current. STATCOM has become a promising reactive power compensation device in power system which has a very broad market prospects because of those advantages.Voltage source inverter is the basic composition for most of the operational STATCOM at present. The allowed witching frequency of power electronic devices is getting lower as the compensation capacity increases, which is a serious problem for STATCOM especially when it is applied in large capacity reactive power compensation system. Device series and parallel technology and multiple techniques are defective in voltage-sharing and current-sharing issues, thus reducing the reliability of the main circuit. Therefore, it is of great significance to study multiple parallel-operational modular STATCOM to gain larger capacity of reactive power compensation. Multiple parallel-operational STATCOM also can improve the flexibility and redundancy of the compensation system portfolio.Based on the standalone STATCOM theory research, this paper suggests several different topologies in multi-parallel system to solve the above issues and analyzes how each part of the compensation units in every topology works. A small STATCOM devices based on digital signal processor is designed which includes selection of the devices, circuit design, cooling system design and software programming. Finally, compensation experiment is carried out successfully, thus verifying the feasibility of the design. |
PDF Full Text Request