Distribution system reliability is directly affected by the placement of various types of protective devices at different locations of the distribution system. To reduce the momentary interruptions, fuse‐blow scheme is used which in turn increases sustained interruption. Utilities having more concern to the sustained interruptions prefer to use fuse‐save scheme over fuse‐blow scheme. Different models have been developed to solve the problems incorporating placement of various combinations of protective devices in a distribution network for increasing the profit of the utility. The uncertainties in temporary failure rates, permanent failure rates, repair rates and load data have been considered in the problem formulation using three‐point estimate method. A generalised objective function capable of simulating different combinations of the protective devices has also been developed. The formulated problems have been solved for 58 bus and IEEE 123 bus distribution networks using mixed integer non‐linear programming optimisation technique. After analysing the test results of the various scenarios for the two test systems, it is concluded that maximum profit for the utility is obtained by using the scenario corresponding to a combination of the four protective devices, namely reclosers, switches, fuse‐blow fuses and fuse‐save fuses.

Because of the rapid increase in the depletion rate of conventional energy sources, the energy crisis has become a central problem in the contemporary world. This issue opens the gateway for exploring and developing renewable energy sources to fulfill the exigent energy demand. Solar energy is an abundant source of sustainable energy and hence, nowadays, solar photovoltaic (PV) systems are employed to extract energy from solar irradiation. However, the PV systems need to work at the maximum power point (MPP) to exploit the highest accessible power during varying operating conditions. For this reason, maximum power point tracking (MPPT) algorithms are used to track the optimum power point. Furthermore, the efficient utilization of PV systems is hindered by renowned partial shading conditions (PSC), which generate multiple peaks in the power-voltage characteristic of the PV array. Thus, this article addresses the performance of the newly developed jellyfish search optimization (JSO) strategy in the PV frameworks to follow the global maximum power point (GMPP) under PSC.

Optimal placement of protective devices and switches in the distribution system improves the system reliability at the cost of increased investment. In this study, a new bi‐directional analytical model has been developed to solve the problem of optimal placement of protective devices and switches in various zones of a distribution system with distributed generation (DG). The model determines the optimal number and locations of reclosers, switches, ‘fuse‐save fuses’ and ‘fuse‐blow fuses’ for increasing the system reliability while reducing the investment and outage costs, considering system data uncertainties. For considering uncertainties in load data, failure rates (temporary and permanent) and repair rates, the model utilises three‐point estimate method. The formulated problem has been solved for 69‐bus distribution system and radial distribution system connected to bus 4 of the reliability busbar test system, using genetic algorithm optimisation technique. After analysing the test results, it is concluded that considerable profit to the utility is achieved by optimal placement of protective devices and switches in various zones of the distribution system with DG units.

This paper used an artificial jellyfish search (AJFS) optimizer suitable for selective harmonic elimination-based modulation for multilevel inverter (MLI) voltage control application. The main objective was to remove the undesired lower-order harmonics in the output voltage waveform of an MLI. This algorithm was motivated by the behavior of jellyfish in the ocean. Jellyfish have the ability to find the global best position where a large quantity of nutritious food is available. The paper applied AJFS algorithm on five, seven, and nine levels of CHB-MLI. The optimum switching angle was calculated for the entire modulation range for the desired lower-order harmonics elimination. The problem formulated to achieve the objective was solved in a MATLAB environment. The total harmonic distortion (THD) values of five-, seven-, and nine-level inverters for various modulation indexes were computed using AJFS and compared with the powerful differential evolution (DE) algorithm. The comparison of THD results clearly demonstrated superior THD in the output of CHB-MLI of the AJFS algorithm over DE and GA algorithm for low and medium values of modulation index. The experimental results further validated the better performance of the AJFS algorithm.

There is a need for the optimal positioning of protective devices to maximize customers satisfaction per their demands. Such arrangement advances the distribution system reliability to maximum achievable. Thus, radial distribution system (RDS) reliability can be improved by placing reclosers at suitable feeder sections. This article presents comprehensive details of an attempt to determine the reclosers’ optimal location in an RDS to maximize the utility profit by reliability improvement. Assessment of different reliability indices such as SAIDI, SAIFI, CAIFI, CAIDI, etc., with recloser placement, exhibits a considerable improvement in these indices in contrast with the absence of recloser. Consequently, a new bidirectional formulation has been proposed for the optimized arrangement of reclosers’. This formulation efficiently handles the bidirectional power flow, resulting from distributed generation (DG) unit (s) in the system. The proposed model has been solved for a test system by utilizing the Genetic algorithm (GA) optimization method. Later, test results conclude that reclosers’ optimal placement contributes significantly towards utility profit with minimum investment and outage costs.

The apparent advantages of Multilevel Inverter (MLI) topologies in handling medium and high power with less loss in switching and lower harmonic distortion in an output voltage waveform makes it better than the conventional inverter. However, the MLI topologies utilize a large number of DC power supplies and power semiconductor devices. They also have a higher value of total standing voltage (TSV). Moreover, capacitor voltage balancing problems, self-voltage boosting inability, and complex control techniques require a relook and improvement in their structure. More recently, Switched-Capacitor Multilevel Inverter (SCMLI) topologies have been proposed to overcome the shortcomings of MLIs. In this paper, a generalized structure for a single-phase switched capacitor multilevel inverter (SCMLI) with self-voltage boosting and self-voltage balancing capability is proposed. A detailed analysis of a general structure of SCMLI is presented. The comparative analysis of the structures is carried out with recently reported topologies to demonstrate superiority. An optimized low-frequency modulation controls the output voltage waveform. The simulation and experimental results are included in the paper for single-unit symmetric (9-level voltage) and asymmetric (17-level voltage) configurations.