Tracking and control of power oscillation dampings in transmission lines using PV STATCOM

Abstract

This paper proposed a new control of PV solar system as a FACTS device STATCOM, called PV-STATCOM, for power oscillation damping (POD) in transmission systems. In this proposed control, as soon as power oscillations due to a system disturbance are detected, the solar farm briefly discontinues its real power generation function and makes its entire inverter capacity available to operate as a STATCOM for POD. As soon as power oscillations are damped, the solar farm restores real power output to its pre-disturbance level while keeping the damping function activated. This results in much faster restoration than that specified in grid codes. During the nighttime, the solar farm performs POD with its entire inverter capacity. The proposed control system provides a significant increase in power transfer capacity on a 24/7 basis in systems that exhibit both local inertial and inter-area oscillatory modes. The developed PV-STATCOM is about 50–100 times cheaper than an equivalent STATCOM for providing POD at the same location. This new control method provides more savings for transmission utilities and opens up a new revenue-making opportunity for solar farms