Zeitschrift für elektrische und elektronische Systeme

Transient Stability Constrained Optimal Power Flow (TSCOPF) is an important tool for power system planning and operation. It is a big challenge in the field of power systems because of its high complexity and extensive computation effort involved in its solution. This paper presents a new approach to compute the transient stability constraint formulated by the Critical Clearing Time (CCT) in TSC-OPF. CCT has been determined by Dual-Kriging, a space interpolation method which has primarily been used in natural resources evaluation. Given the huge dimensionality of the problem, Pareto analysis is firstly used to reduce the number of input variables in an initial database to those which are significant to compute CCT. With the reduced variables, a new database has been constructed using a design of experiment to obtain a reduced number of observed points. As a result of this approach, the sets of dynamic and transient stability constraints to be considered in the optimization process are reduced to one single stability constraint with only a few variables. Finally, the size of the resulting optimization problem is almost similar to that of a conventional OPF. In the new approach, there is no limitation for the machine model. The effectiveness of the proposed method is tested on the New England 10-machine 39-bus system by using detailed model and the larger power system 50-machine 145-bus power system.

It is commonly accepted that designing Single Tuned Passive Filters (STPFs) is an optimization problem. By choosing the best passive filter, this work seeks to enhance the power quality of an actual distribution system in Tala city as a part of Egyptian network. Although the distribution feeder already has a passive filter, there are still some power quality problems. By using Jelly Fish Optimization Technique (JFOT) and Arithmetic Optimization Algorithm (AOA) to improve the placement and size of the low pass harmonic filter, this paper intends to cut overall power loss and reduce the influence of total harmonic distortion. The suggested filters' cost, real power losses, Total Harmonic Distortion ("THD"), and Individual Harmonic Distortion ("IHD") are optimized using single and multi-objective functions, respectively. Inequality constraints are used to establish upper and lower limits for filter parameters, quality factor, voltage, and harmonic distortion. The power balance constraint on equality will be applied. The results indicate that an optimally designed of STPF can successfully reduce high order harmonics and enhance system performance of STPF under various operating conditions to consistently follow to the established IEEE 519 standards'.