The IUP Journal of Electrical and Electronics Engineering
Capability of SEN Transformer in Low Frequency Oscillation Damping

Article Details
Pub. Date : April, 2019
Product Name : The IUP Journal of Electrical and Electronics Engineering
Product Type : Article
Product Code : IJEEE61904
Author Name : Nemat Talebi, Behzad Taghizadeh and Bala Subramanyam
Availability : YES
Subject/Domain : Management
Download Format : PDF Format
No. of Pages : 11



FACTS devices are important in controlling power in a line and voltage amplitude at steady state and dynamic conditions. They perform well in suppressing power system oscillations while improving the damping and are based on power electronics technology supported by advanced control techniques. The paper proposes a new device SEN Transformer (ST) to damp Low Frequency Oscillations (LFOs) considering the techno-economic feasibility. ST has conventional technology of transformers and tap changer settings. The operational speed of tap changer switching determines the response time of damping controller, which is quite adequate (with simple electronic switches) in most utility applications.


SEN Transformer (ST) is a three-phase transformer equipped with on-load tap changer. It can produce a controlled voltage with respect to amplitude and phase angle. This controlled voltage is in series with the secondary ST, so it is in series with the transmission line. Consequently, it can control amplitude and phase angle of sending end bus voltage (Sen and Sen, 2003a). The user can regulate the voltage of ST based on the application. The main point is that, in cases where there is no need of fast dynamic response, an ST can suppress Low Frequency Oscillations (LFOs) adequately. On the other hand, the main objective is controlling the rotor angle oscillations in LFO stability. Since ST has the ability of fast controlling of amplitude and phase of voltage, it is an appropriate alternative to conventional Power System Stabilizer (PSS) in damping LFO. A unified Phillips-Heffron model of single machine infinite-bus power system with Static VAR Compensator (SVC), Controllable Series Compensation (CSC) and Phase Shifter (PS) are considered for damping power system oscillations (Wang and Swift, 2007).


Low Frequency Oscillations (LFOs), FACTS devices, Electrical tap changer, SEN Transformer (ST), Synchronous machines Phillips-Heffron model, Power system oscillation, Damping