Hybrid Method For Calculating The Maximum Loading Point Using Continuation Load Flow And Nonlinear Programming Techniques

The computation of the maximun loading point (MLP) is crucial to power systems operation and control, There are several methodologies proposed to compute it. The continuation load flow (CLF) is very robust, widely known to draw PV curves, and can be also used for computing the MLP. However it has some drawbacks, the procedure may diverge for some cases and it is very conservative for some networks, taking many iterations. Other efficient technique using nonlinear programming (NLP) has been proposed recently. This method presents clear advantages due to the orientation of the process in direction to the MLP. This paper presents a method based on the CLF and NLP . The idea is to compute the MLP taking some features of the CLF combined with characteristics of NLP. With this combination the MLP can be evaluated with more accuracy and efficiency. Simulations for different systems including IEEE test systems are shown to evaluate the performance of the method. Some comparisons of the methodologies are also shown. ©2007 IEEE.19291934Kundur, P., (1994) Power System Stability and Control, , McGraw- HillDefinition and classification of power system stability (2004) IEEE Transactions on Power Systems, 19 (2), pp. 1387-1401. , IEEE/CIGRE, MayVan Cutsem, T., Moisse, C., Mailhot, R., Determination of secure operating limits with respect to voltage collapse (1999) IEEE Transactions on Power Systems, 14 (1), pp. 327-335Souza, A.C.Z., Cañizares, C., Quintana, V., Comparison of performance indices for detection of proximity to voltage colapse (1996) IEEE Transactions on Power Systems, 11 (3), pp. 1441-1450Ajjarapu, V., Christy, C., The continuation power flow: A tool for steady state voltage stability analysis (1992) IEEE Transactions on Power Systems, 7 (1)Zarate, L.A., Castro, C.A., Jose Luis, M.R., Esther, R.R., Fast computation of voltage stability security margins using nonlinear programming techniques (2006) IEEE Transactions on Power Systems, 21 (1), pp. 19-27Zárate, L.A., Castro, C.A., Fast computation of security margins to voltage collapse based on sensitivity analysis (2004) IEE Proceedings - Generation, Transmition and DistributionFlatabø, N., Ognedal, R., Carlsen, T., Voltage stability condition in a power transmission system calculated by sensitivity methods (1990) IEEE Transactions on Power Systems, 5 (4). , NovIrissari, G.D., Wang, X., Mokhtari, S., Maximum loadability of power system using interior point nonlinear optimization method (1997) IEEE Transactions on Power Systems, 12 (1). , FebBedoya, D.B., Castro, C.A., Computation of power systems minimum voltage stability security margins (2006) IEEE/PES POWERCON 2006 International conference on power systems technology, Chongqing, , China, 22-26 OctoberL. M. Braz and C. A. Castro and C. A. F. Murari. A critical evaluation of step size optimization based load flow methods. IEEE Transactions on Power Systems, 15, no. 1:202-207, Feb. 2000Seydel, R., Practical Bifurcation and Stability Analysis. From Equilibrium to Chaos (1994) Springer Interdisciplinary Applied Mathematics, , Second Edition, Springer, New YorkDobson, I., Lu, L., New methods for computing a closest saddle node bifurcation and worst case load power margin for voltage collapse (1993) IEEE Transactions on Power Systems, 8 (3