Power System Transient Stability Study by Involving Higher Order Corrections in Improved Quadratic Lyapunov Function for Singular Perturbed Model of Synchronous Generator

Abstract

The assessment of transient stability of multi-machine power system, in a post-fault scenario, is a very challenging task due to highly non-linear nature of the system equations. In this work, the physical concept of maximum relative acceleration of a machine at a fault scenario is related with the boundary of stability region. This approach is extended to develop a quadratic Lyapunov function using singular perturbed modelling. Unlike the conventional energy function methods, this Lyapunov function candidate is a more general energy function and has a decaying nature around an equilibrium point. Moreover, with higher order corrections, an improved Lyapunov function candidate is presented with simulation results of power system examples. The decaying nature of Lyapunov function candidate remains similar even without higher order corrections. However, the relevance of inclusion of higher order corrections is brought out in the cases of faults occurring at other than generator buses. Also, the upper bound of singular perturbation parameter in the model is within allowable limits and ensures the accuracy of results.

KEYWORDS:

• Acceleration
• Critical clearing time
• Lyapunov’s second method
• Singular perturbation
• Transient stability
• Upper bound

Additional information

Notes on contributors

Sunitha Anup

Sunitha Anup is a research scholar in the Centre for Energy Studies, IIT Delhi, India. She received her BTech from NIT, Calicut, and MTech from University of Mumbai. Her research interests are Power System and non-linear dynamics. Corresponding author. Email: [email protected]

Ashu Verma

Ashu Verma is an assistant professor in the Centre for Energy Studies, IIT Delhi, India. She received her MTech and PhD both from Department of Electrical Engineering, IIT Delhi. She has more than 10 years of teaching experience and several research papers in her field. Her present research interests are power system planning, operation and control aspects of integrated renewable energy systems, policy and regulatory framework for enabling large-scale integration of renewable energy sources in India. Email: [email protected]

T.S. Bhatti

T S Bhatti is a professor in the Centre for Energy Studies, IIT Delhi, India. He did his PhD from IIT Delhi and was a post-doctoral fellow at University of Newcastle, Australia. He is the secretary of Central Research Committee since 2003 and has published several research papers in reputed journals. His research interest includes automatic generation control of power systems, transient stability analysis of multi-machine systems and air concentrating nozzles and drag type vertical axis wind energy conversion systems. Email: [email protected]