一种新型的UPFC拓扑

提出了统一潮流控制器的一种新型拓扑,它包含两个交流侧面对面连接,而不是通过公共直流环节背对背连接的逆变器.该新型结构具有以下优点:1)两个逆变器间没有有功功率交换,两个逆变器仅提供或吸收无功功率;2)级联式逆变器可以用于这种结构,因而取消了传统的磁接口--曲折变压器,大幅度减少了功率损耗;3)在许多负载情况下,所需要的逆变器容量可以大大减少;4)模块化的级联式逆变器和它的冗余性使得这种新型结构更具设计的灵活性和实现的可靠性.仿真结果清楚表明:在所需的容量方面,新型拓扑比传统拓扑更具优势,实用,实现更容易.

A Novel Configuration of Unified Power Flow Controller

The paper proposes a novel configuration of Unified Power Flow Controller (UPFC).The proposed configuration has two inverters connected face to face on the ac side instead of connected back to back through a common DC link.The new configuration has the following advantages:1) there is no active power exchange between the two inverters and both inverters only provide or absorb reactive power;2)cascade multilevel inverters can be used in the configuration,thus eliminating the conventional magnetic interface zigzag transformers,and greatly reducing power losses;3)the total required VA rating of the inverters can be reduced greatly over a wide load conditions;4)The new configuration with modular cascade multilevel inverters and their redundancy has greater flexibility to system design and realization of higher reliability.The simulation results clearly show that the novel UPFC is feasible and advantageous over the conventional UPFC in terms of required VA rating.