The Research Of The10kV Unified Power Flow Controller With Solid-state Fault Current Limiter Industry Prototype

In Flexible AC Transmission System(FACTS) family the unified power flow controller (UPFC) can flexibly optimize control of the power flow, with comprehensive regulating three important parameters of the transmission line (voltage, phase angle and impedence), therefore improve the power system dynamic performance and running quality effectively,and be regarded as the most powerful FACTS device at the moment. But the series inverter of UPFC must be capable of withstanding the impact of the system high-voltage and the large fault current when a short circuit fault occurs in the power system, otherwise the whole devise will be damaged in a short time.While aiming at this issue, a new type of FACTS device called Unified Power Flow Controller with Fault Current Limiting (UPFC-FCL) is proposed and researched by Zhejiang University. The device is equivalent to the regular UPFC in normal condition of the power system;when a short circuit fault occurs,it will turn out to be the fault current limiting condition and the direct current limiting inductance will immediately and automatically insert in the second-side circuit of the coupling-transformer to limit the fault current to less than the set level as well as protect UPFC from being damaged by the impact of the high-voltage and short circuit.The main circuit topology and basic characteristics of UPFC-SSFCL is introduced in the paper as well as the detailed current limiting process and control measures. It also develops a10kV/1MVA model experimental prototype of UPFC-SSFCL, including the main circuit equipment (components) parameters introduction, detailed description of second-side control system design and laying out lOkV experimental schemes Moreover, the low voltage test is completed. The results show the correctness of the theoretical analysis and effectiveness of the device of UPFC-SSFCL.