VSC的FACTS元件对动态电能质量的影响

Study on impacts of VSC-based HVDC upon dynamic power quality

鉴于目前研究的FACTS装置很大一部分运用到VSC这一事实,介绍了基于VSC的UPFC,HVDC和SMES的原理和工作过程,利用PSCAD/EMTDC软件包分别建立了它们的时域模型;从动态电能质量的角度出发,分析在系统稳态、遭受两相短路故障、输电线路雷击和系统含谐波源情况下,基于VSC的UPFC,HVDC和SMES装置对动态电能质量的影响。将其结果与未安装这些FACTS装置下的波形进行比较,结果表明,采用基于VSC的UPFC,HVDC和SMES技术将使系统动态电能质量得到改善。

FACTS technique (Flexible Alternating Current Transmission Systems technique) is forecasted as one of the main support techniques in the future. FACTS are capable of regulating line voltage, controlling line load-flow, damping system oscillation and improving transient stability. Based on the fact mat a majority of FACTS controllers utilize bom shunt-connected and series-connected Voltage-Sourced Converters (VSC), the theory and operation process of UPFC, VSC-HVDC and VSC-SMES are briefly reviewed. The time-domain models with UPFC, VSC-HVDC and VSC-SMES are designed by using PSCAD /EMTDC software package. From the dynamic power quality point of view, the effects of VSC-based FACTS on the systems under steady-state and the one under the situations when a fault happened, a line was stricken by a lightning, and a harmonic source was added into the system, are discussed. In comparison with the results of systems without any FACTS controller under the same situations, VSC-based FACTS will improve the power system dynamic power quality.