Studies on Accuracy of Higher Order Normal Forms Applied to Power System Analysis Using Neumann Series Convergence Criterion

This paper investigates the accuracy of normal form analysis applied to power systems. The steps involved in the method of normal forms are described. The approximations involved in the method of normal forms which can lead to inaccurate results are given. The accuracy of the method is dependent on the convergence of Neumann series used to obtain the inverse of a matrix in one of the steps. Studies on the convergence of Neumann series are conducted on a SMIB system. The region of convergence of Neumann series in the phase plane is determined.