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A method is proposed for allocating generation so as to maximize power transfer between areas of interconnected systems under transient stability constraints. This "transient stability-constrained maximum allowable transfer" (for short MAT) method consists of screening a large number of contingencies, scrutinizing the dangerous ones and suggesting generation rescheduling patterns to stabilize them. The MAT method is based on SIME, a hybrid transient stability method. Like SIME, MAT is accurate and free from simplifying assumptions about modelling, stability scenarios and instability modcs. In addition, by controlling all dangerous contingencies siniulfuneously, the method succeeds in being fully compatible with requircments for real-time preventive monitoring and control. The method is illustrated on the South-Southeast Brazilian power system, operating under highly stressed conditions imposed by large power transfer between areas.

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This paper presents an extended formulation for fault location on electric distribution systems based on one-terminal measurement of apparent impedance. The method is developed using phase-components analysis to account for the inherent unbalanced operation of distribution feeders. Since distribution loads present a stochastic variation through time, a technique for compensation of load variation in both magnitude and angle is also presented. The proposed developments include two general fault location equations that account for any fault type. An iterative algorithm to compensate the line capacitive current component is also provided, thus enabling the application of the technique to long rural and underground systems, in addition to overhead distribution systems. Test results show the accuracy and robustness of the fault location algorithm to different fault types, distances and resistances, considering system's load profile variations up to ± 50%.

Stability is an important constraint in power system operation. Often trial and error heuristics are used that can be costly and imprecise. A new methodology that eliminates the need for repeated simulation to determine a transiently secure operating point is presented. The methodology involves a stability constrained Optimal Power Flow (OPF). The theoretical development is straightforward: swing equations are converted to numerically equivalent algebraic equations and then integrated into a standard OPF formulation. In this way standard nonlinear programming techniques can be applied to the problem.

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This paper presents an analytical mixed-integer linear programming model to improve reliability of distribution networks through the optimal allocation of automated switching devices. Optimal reliability is formulated as a multi-objective problem of minimizing customers' interruptions and the investment costs related to devices' acquisition, relocation and operation. In order to establish the optimal trade-off between these conflicting objectives the Goal Programming approach is proposed. The presented model considers post-fault restoration constraints which limit load transfers and thereby the system reconfiguration capability. Restoration feasibility is ensured by a linear formulation of power flow equations as functions of geographical locations of automated switching devices in the feeder. Therefore, the model's solutions provide a more effective and economic application of automated switching devices, so that voltage and system capacity constraints are taken into account in selecting optimal locations of devices. The proposed methodology was validated using the IEEE 123-bus test feeder.Index Terms--Allocation of automated switching devices, Distribution systems reliability, Load restoration, Mixed-integer linear programming.I.