Sensitivity approaches for direct computation of critical parameters in a power system

Abstract

In this paper we propose two techniques to estimate critical values of parameters of interest in a power system such as clearing time of circuit breakers, mechanical input power, etc. One is via the sensitivity of the transient energy function (TEF) and the other through computation of the norm of the trajectory sensitivities. Both these methods require some a-priori information about the range of the critical parameters. In real time operation, this information is generally available to the operator. A changing operating condition will result in new values of the critical parameters and the proposed technique can thus monitor them closely without the use of direct methods. The advantage of the first technique lies in not having to compute the unstable equilibrium point (uep) while in the second technique even the computation of stable equilibrium (sep) is not needed. However, there are additional computational costs involved in both the techniques, which can be addressed by faster algorithms for computing the sensitivities.