132-Mvar 35-kV STATCOM Equipped With a Novel Power Oscillation Damping Control Strategy

This article presents a 132-Mvar 35-kV STATCOM equipped with a novel power oscillation damping (POD) controller which is able to damp the network interarea low-frequency oscillations. The transmission system is modeled as a three-bus network to which the static synchronous compensator (STATCOM) is connected and whose dynamics are captured by means of the small-signal approach. Then, the relevant system transfer functions are derived. Through the analysis, it is found that the upstream network exhibits and undamped oscillatory response in the presence of perturbations. Thus, the control strategy proposed here first introduces a damping action. Then, to improve the transient performances, a proportional-derivative (PD) regulation on the point of common coupling (PCC) voltage angle is presented. An algorithm able to extract and filter the upstream network variables involved in the control process is also provided. The effectiveness of the POD control strategy developed in this work is, therefore, verified in simulation, and its regulation performances are discussed in detail. Finally, the converter has been deployed and connected to a high-voltage substation. The experimental tests carried out on the field that demonstrates the validity and the proper operation of the POD control proposed in this article, under both inductive and capacitive modes of the converter.