The efficient use of energy is a priority when a technology migration plan is being executed. Several factors must be taken into account in order to achieve this goal. In this paper the migration from liquefied petroleum gas based cookers to electric induction cookers is analyzed, emphasizing on the selection of the best material to produce the cookware suitable for induction cookers in terms of energy saving and performance. To accomplish this study, several tests have been performed in three kind of pots made of different materials: stainless steel, cast iron and aluminium. These tests have allowed to evaluate some material properties as rust resistance, structural stability of pot bottom under thermal impact conditions, energy efficiency measurements in different body cookware materials, energy efficiency with different distances between induction zone and pot bottom, relation between energy efficiency and initial measurements of concavity/convexity and energy efficiency before and after thermal impact conditions. After completing this research, it has been found that the enameled cast iron and the stainless steel present higher efficiency in the same stove

An electrical power system (EPS) is subject to unexpected events that might cause the outage of elements such as transformers, generators, and transmission lines. For this reason, the EPS should be able to withstand the failure of one of these elements without changing its operational characteristics; this operativity functionality is called $N-1$ contingency. This paper proposes a methodology for the optimal location and sizing of a parallel static Var compensator (SVC) in an EPS to reestablish the stability conditions of the system before $N-1$ contingencies take place. The system’s stability is analyzed using the fast voltage stability index (FVSI) criterion, and the optimal SVC is determined by also considering the lowest possible cost. This research considers $N-1$ contingencies involving the disconnection of transmission lines. Then, the methodology analyzes every scenario in which a transmission line is disconnected. For every one of them, the algorithm finds the weakest transmission line by comparing FVSI values (the higher the FVSI, the closer the transmission line is to instability); afterward, when the weakest line is selected, by brute force, an SVC with values of 5 Mvar to 100 Mvars in steps of 5 Mvar is applied to the sending bus bar of this transmission line. Then, the SVC value capable of reestablishing each line’s FVSI to its pre-contingency value while also reestablishing each bus-bar’s voltage profile and having the lowest cost is selected as the optimal solution. The proposed methodology was tested on IEEE 14, 30, and 118 bus bars as case studies and was capable of reestablishing the FVSI in each contingency to its value prior to the outage, which indicates that the algorithm performs with 100% accuracy. Additionally, voltage profiles were also reestablished to their pre-contingency values, and in some cases, they were even higher than the original values. Finally, these results were achieved with a single solution for a unique SVC located in one bus bar that is capable of reestablishing operational conditions under all possible contingency scenarios.

In this research, an alternative methodology is proposed for the location of Static VAR Compensators (SVC) in power systems, considering the reconfiguration of reactive power flows through the optimal switching of the transmission stage, which resembles the contingency restriction N-1 usually considered in transmission expansion planning. Based on this methodology, the contingency index was determined, which made it possible to determine which is the contingency that generates the greatest voltage degradation in the system. For the quantification of reactive flows, optimal AC power flows were used, which minimize the operating costs of the power system subject to transmission line switching restrictions, line charge-ability, voltages and node angles. To determine the node in which the compensation should be placed, the contingency index criterion was used, verifying the voltage profile in the nodes. The proposed methodology was tested in the IEEE test systems of 9, 14 nodes and large-scale systems of 200, 500 and 2000 bus-bars; to verify that the proposed methodology is adequate, the stability of the EPS was verified. Finally, the model allows satisfactorily to determine the node in which the SVC is implemented and its compensation value.

The reliability of the electrical system is a fundamental study that is carried out to determine the possible deficiencies that an electrical system can have in case of failures, since a failure can cause disturbances, power cuts, and load disconnections. For this reason, Optimal Transmission Switching (OTS) with Optimal AC Power Flows (OPF-AC) is used to reduce disturbances when faults occur and minimize equipment load and disconnections, but OTS offers possible switches in order to make it possible to reduce the damage that can be done for a fault with operating limitations in voltage, power, and angular deviation. However, to have a complete study, it is proposed to use a reliability analysis through contingency ranking to know the risks that a switched system may have at the time of simultaneous or consecutive failures. In addition, a load capacity investigation is conducted to determine if the transmission lines are within their operating limits. The study presents an analysis of the behavior of the switched system and an adequate operation for the mitigation of failures in the system through the switching of transmission lines with analysis of load capacity and reliability. The results presented by the proposed methodology will be compared with Matlab’s Matpower simulation package.

Optimal transmission switching allows to make different types of analysis focused on improving the functionality of electrical power systems. The implementation of this method along with contingency analysis seek to increase the flexibility of the electrical system through changes in network topology and power flow redirection. In this article, an analysis is carried out about the impact of transmission line switching in terms of loadability and voltage angles. The optimal transmission switching model used is formulated using optimal DC power flows as a mixed-integer linear program problem. The research considers simple contingencies with the loss of at least one transmission line and it contrasts the results obtained in three scenarios; without contingencies and switching actions, optimal switching without contingencies and optimal switching after a contingency has occurred. The results obtained show a small number of unviable solutions prior to the implementation of switching actions. This exposes the clear possibility of applying line switching even when a contingency has occurred without losing load and keeping costs low.

This article proposes an analysis of energy losses in distribution circuits with asymmetric topologies, starting from mathematical comparisons of the parameters of electrical losses among the three constructive approaches for distribution networks (monophasic, biphasic and three-phase). Approximations, that allow us to know asymmetric loss factors, will be established in order to develop appropriate criteria of designs in distribution networks that feed transformers purely monophasic, depending on the charge states, caliber of drivers and distances of the lines; thus minimizing the losses of energy due to unbalanced construction concept. These obtained factors provide a tool for the optimum design of more efficient networks, either to correct inefficient systems with high levels of losses, which are already in operation, or for new electrical investments projects pointing to the development of future smart grids with high energy efficiency.