Elimination of Chaotic Ferroresonant Oscillations Originated from TCSC in the Capacitor Voltage Transformer

ABSTRACT

Ferroresonance is one of the complex phenomena, which occurs in power network. This can create thermal and insulation problems in the power system equipments. It can also cause chaotic oscillations in the power network. The magnitude of the power system capacitor is one of the important factors that lead to ferroresonance in capacitor voltage transformers (CVTs).

Thyristor controlled series capacitors (TCSCs) are applied for series compensation in the transmission line of power system. In normal operation, these equipments have capacitance magnitude up to three times of fixed capacitor such that the increased value of transmission line capacitor, which is one of the reasons for ferroresonance occurrence, is provided. This paper studies and investigates the effects of TCSCs on the ferroresonance in the CVTs. Because of nonlinear dynamics of ferroresonance, bifurcation theory is utilized in this paper. Using this theory, variation of system parameters that cause chaotic ferroresonant oscillations can be efficiently analyzed. By using bifurcation and phase plane diagrams, behavioral variations of the system with TCSC can be easily reviewed in this case. The results show that TCSCs raise ferroresonance occurrence in CVT. Since thermal and insulation problems may happen during the occurrence of ferroresonance in CVT and TCSC, a device is used to limit and remove these chaotic oscillations; literally called ferroresonance limiter. Obtained results strongly and efficiently show effectiveness of using this method for restricting ferroresonant oscillations.

KEYWORDS:

• Bifurcation
• Capacitor voltage transformer (CVT)
• Chaos
• Ferroresonance
• Nonlinear dynamics
• Thyristor controlled series capacitors (TCSCs)

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Ataollah Abbasi

Ataollah Abbasi received his BS and MSE degrees in electrical engineering from Shahed University, Iran, in 2005 and 2008, respectively. Currently, he is pursuing his PhD degree in electrical engineering at the Electrical Engineering Department of AUT, Tehran, Iran. His research interests are in the application of artificial intelligence to power system control design, analyzing chaos in power systems, analyzing resonance and ferroresonance phenomena, and chaos control in power systems.

E-mail: [email protected]

Seyed Hamid Fathi

Seyed Hamid Fathi received his BSc and MSc degrees in electrical engineering from Amirkabir University of Technology (AUT), Tehran, Iran, and IIUST, Tehran, Iran, in 1984 and 1987, respectively. He gained his PhD degree in electrical engineering from the University of Newcastle-Upon-Tyne, UK, in 1991. Then, he joined AUT and currently he is an associate professor at the Electrical Engineering Department of AUT. His research interests include power quality, flexible ac transmission systems (FACTS), power electronics, and electric drives.

E-mail: [email protected]

Amin Mihankhah

Amin Mihankhah received the BSc and MSc degrees in electrical engineering from University of Tehran, Tehran, Iran in 2009 and 2012, respectively, and is currently working toward the PhD degree in electrical engineering from Amirkabir University of Technology (Tehran Polytechnic). His research interests include nonlinear control, chaos, system identification, control of power systems, and robotics.

E-mail: [email protected]