Analysis on the Transmission Line Power Flow Control Strategy of the UPFC Project in Western Nanjing Power Grid

Among the versatile control strategies in the control system of unified power flow controller (UPFC), the transmission line power flow control strategy is the most important one, which can help UPFC to realize its core function of regulating power flow. Based on the UPFC project in western Nanjing power grid, which is the first modular multilevel converter (MMC) based UPFC project all over the world, the function configuration and hierarchical structure of the UPFC control system are introduced firstly in this paper. Besides, the details of the transmission line power flow control strategy are presented. With the above control strategy, the active power and reactive power of the transmission line can be regulated quickly, independently and safely. Eventually, the field test results are demonstrated to validate the effect of the above control strategy.