The Effect of FACTS Devices on Voltage Sag Following Transformers Inrush Current and Short Circuit Faults

Power quality has a high dependence on short-term voltage changes. Voltage changes can cause damage to sensitive electronic equipment. Voltage sag is one of the short-term voltage changes that can be due to various factors, such as the inrush current of the transformers during switching in the presence of large loads or during short circuit faults. An important issue in the discussion of voltage sag is the rate of voltage recovery to a stable value. In this paper, three different compensators, Static Var Compensator (SVC), Thyristor Controlled Series Capacitor (TCSC), and Static Synchronous Series Compensator (SSSC), which are considered flexible AC transmission system (FACTS) devices, have been used to reduce the inrush current during switching of the transformers and consequently reduce the voltage sag caused by this event. Also, the efficiency of these devices has been investigated to increase the voltage recovery rate after clearing various transient faults in the network, which are the main innovations of the present study. To evaluate and validate the results, a double-fed network modeled in PSCAD software is used. The results of the simulations will show that the compensators used in this research improve the voltage sag by limiting the current and will significantly improve the rate of voltage recovery to a stable value after clearing various faults.

کلیدواژه ها:

FACTS ، Inrush Current ، Power Transformer ، Short circuit Faults ، Voltage Sag