Abstract

Power system operators are often faced with the challenge of identifying the dynamic operating security modes during the on-line operation of the power system, which requires fast, accurate and reliable evaluation techniques. The system security constraints are in fact boundaries that surround all possible operating modes (scenarios) of the power system. In other words, these boundaries form the feasible operating domain - in the parameter space spanned by various operating variables - within which the system can safely be operated. For a given operating scenario, the associated security level is measured by the “distance” (for example, the Euclidean norm) of the operating point from the security region boundary. This paper presents a novel methodology and computerized scheme, which are capable of identifying dynamic operating security modes during the on-line operation of electric power systems. The methodology adopted in this paper includes the development of advanced, highly efficient computerized algorithms for fast identification of dynamic operating security modes of power systems. One of the salient outcomes of this paper is the development of a novel framework for identification and representation of operating security regions in power systems as well as evaluation of security levels associated with different operating scenarios. While the concepts and principles presented are general, the work of this paper is confined to the interpretation of the security boundary in terms of system stability criteria. In addition, the framework presented is applicable quite as well to other criteria that may be considered.

Key words: Power system operation, security regions, system stability, operating constraints.