UPFC的直接电压控制及其应用

摘要

Unified power flow controller (UPFC) is a powerful FACTS device, which can regulate the power flow and voltage. But now there is few research on series side voltage control of UPFC. Most of the existing control strategies are based on direct current control. On the basis of the mathematical model of UPFC in two-phase dq rotary coordinate system and combining feedforward control with PI feedback control, the paper pre-sents direct voltage control strategy of UPFC, which needs no current inner-loop, simplifies control structure and improves control speed. The direct voltage control strategy of UPFC is particularly suitable for UPFC to supply power for passive networks and is resistant to surge load or voltage sag. A simulation model is built in PSCAD/EMTDC, which demonstrates that the direct voltage control strategy of UPFC has a good ability to re-sist surge load or voltage sag by the simulation of motor starting and voltage sag simulation.%UPFC是一种功能强大的FACTS装置，具有潮流调节和电压调节作用。但目前关于UPFC串联侧定电压的控制策略研究较少，且已有的控制策略大多基于直接电流控制。以UPFC在dq两相旋转坐标系下的数学模型为基础，将前馈和PI反馈控制相结合，给出了UPFC的直接电压控制策略，无需电流内环，简化了控制结构，提高了控制响应速度。 UPFC的直接电压控制策略特别适合于UPFC向无源网络供电，具有良好的抗冲击负荷和抗电压跌落的能力。在PSCAD/EMTDC软件中搭建了仿真模型，通过电动机启动和模拟电压跌落仿真，证明了UPFC直接电压控制策略能够较好的满足抗冲击负荷和抗电压跌落要求。