This paper proposes two hybrid control schemes: NGH scheme combined with a thyristor-controlled resistor bank and phase imbalance scheme combined with a thyristor-controlled resistor bank, for damping torsional oscillations of a series-capacitor compensated power system. The IEEE Second Benchmark Model, system-1, which contains a turbine-generator set connected to an infinite bus through a series-compensated network, is properly selected as the studied standard system. The thyristor-controlled resistor bank is properly connected to the studied generator bus while NGH scheme controls the firing angles of the thyristors connected to series-capacitor banks of me transmission lines. Phase imbalance scheme inserts resonant circuits into two phases of three-phase series-capacitor banks to result in three-phase unsymmetrical reactances when the operating frequency deviates from nominal power frequency. The proposed thyristor-controlled resistor bank is respectively combined with NGH scheme and two types of phase-imbalance scheme to render appropriate damping to enhance transient stability limits of the studied system during a severe three-phase short-circuit fault. The ElectroMagnetic Transients Program (EMTP) is utilized to simulate and compare the damping performance respectively provided by the two proposed hybrid control schemes. It can be concluded from the simulated results that the proposed hybrid control schemes can effectively provide adequate damping for the torsional modes of the studied system subject to a severe three-phase short-circuit fault.
|Number of pages||9|
|Journal||International Journal of Electrical Engineering|
|Publication status||Published - 2007 Dec 1|
All Science Journal Classification (ASJC) codes
- Electrical and Electronic Engineering