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Power factor plays an important role in electrical industries. Low power factor results in loss of power and poor handling capacity. This factor can be overcome by using capacitors in parallel to the load. Since capacitor draws a leading while inductor draws a lagging current, hence by adjusting capacitor banks parallel to the load, it will level the power factor in the line. Earlier, the process of power factor improvement was done through manual connection of capacitor bank. Later a power factor corrector named the automated power factor corrector (APFC) was proposed. It uses a switched capacitor circuit to improve power factor. In this research, the power factor value from the load is measured and it also includes the installation of APFC unit using a PI controller. The design of this auto-adjustable power factor correction scheme is to ensure that the grid power system always operates under the specified power factor. Actual work of APFC is that it selects the capacitor bank for power factor improvement. The capacitor bank block will choose automatically to further improve the power factor. This process goes on until the required power factor is obtained. Later on, this will automatically turn off the connection between the capacitor bank and the circuit. Furthermore, power saving with power factor after improvement is also discussed in the paper. Here APFC plays a key role in order to decrease the time taken to correct the power factor, which is ultimately beneficial to increase the efficiency of the motors and all inductive loads.

Electric cars have a lot of promise in future energy markets as a manageable load. A popular vehicle-to-grid control interface, which enables the aggregation of the charging mechanism for energy management in the distribution grid, is one of the most significant road blocks to realize this opportunity. Understanding the ecology of electric transportation and integrating it in local communities to alleviate the energy shortage at peak hours is very complicated. In this research paper, recent standardization initiatives aimed at overcoming obstacles such as the integration of electric cars into smart grids are discussed. A charge control scheme focused on vehicle-to-grid connectivity is implemented. It is observed that the rise of environmentally sustainable energy sources, such as photovoltaic (PV) and wind energy, is straining the power network and their infrequent power generation is causing problems in power system operation, regulation and planning. The introduction of electric vehicles (EVs) into the electricity grid has been proposed to overcome grid load variations. Finally, the article discusses the incorporation of renewable energy sources and latest potential solutions involving electric vehicles.

This article offers an overview of distributed generation (DG) in distribution systems (DS). The primary goal of this study is to assess the performance of DGs in DS. Due to the rise in electrical energy consumption, it is anticipated that DG sources would be essential to DS. Future power generating networks have a bright outlook on consideration of DG’s potential for utilising alternative energy sources. The quality of power systems is a crucial concern for energy providers and consumers. In order to decrease reliance on fossil fuels for the production of electricity, distributed generations are gaining importance in the energy supply networks in many countries. Distributed generators are small units that generate electricity close to customer sites. These DGs use renewable energy methods such as wind energy, solar energy and geothermal energy. The incorporation of DGs into a conventional power supply system evolves in a number of side effects, including an increase in the number of short circuits, higher power losses, a decrease in the quality of the energy produced, voltage transients, problems with voltage stability, coordination issues regarding voltage regulation and protection, the possibility that system protection will not function correctly, and the fact that there is less residual current input as a result of the DG bidirectional power flows. This review paper discusses the impacts of the penetration of DG into DS and provides various strategies to mitigate these effects.

The major shortcoming in the extraction of electrical energy occurs due to partial shading over a limited area of vast spread solar panels underpinning reduction of efficiency. A number of panels are interconnected in series and parallel to form a photovoltaic (PV) array for large power plants and a shadow over a single cell deteriorates overall performance. As a consequence, several peaks are added to the P-V curve causing hotspots in PV panels, degradation of the PV system, and collapse of tracking algorithms. In order to minimize such issues in PV panels, an effective optimization technique is developed by reconfiguring the panels which are capable of reaching the full global power point in a PV system under partial shading conditions. The study proposes particle swarm optimization (PSO) using PV characteristics of Quaid-e-Azam Solar Plant (QASP) in Punjab, Pakistan1. In PSO, electrical connections of PV modules are changed keeping their physical locations unaltered aiming to improve the performance of the PV system. After reconfiguration, the algorithm finds the best combination of PV modules by equalizing the row currents followed by the comparison of row current, voltages, and power of panels. The proposed PSO is proved to be an efficient method for reconfiguring PV modules in very less computational time by increasing the output power of shaded modules.

The protection of power system is an essential trait in a huge network to efficiently detect and isolate the sections undergoing faults or abnormal behaviour. The key components of a protection scheme include circuit breakers, relays, switchgears and fuses which employ communication from one station to another to achieve high-speed tripping. The automation of these components at the laboratory level using programmable logic controller (PLC) along with supervisory control and data acquisition (SCADA) system owns paramount importance for intelligent decision making, sensing, actuating, monitoring and maintaining the record in the host server. This paper discusses such a technique for conventional power system protection laboratory at a new level of development to promote a control system through PLC and SCADA. The control system has indication of over and under values of voltage, load and frequency, which can trigger malfunctioning of equipment and must be rectified. Furthermore, ground fault and inverse current indication are added to the system for monitoring and controlling purposes. The proposed system enhances the efficiency and safety of the expensive equipment and the personnel to the next level and also introduces new standards of automated protection schemes for modern technical institutes.

In an electrical power system, the ultimate aim is to generate and deliver electrical energy to consumer side with minimum cost involved. Thus, least fuel cost, effective unit commitment and minimum transmission losses are desirous to achieve economic dispatch in a distributed generation network. In this research, economic dispatch considering transmission losses in a distributed generation network of Bahawalpur is reported. A MATLAB algorithm is designed which gives optimum division of power between two power plants and their transmission losses. Power plants considered here are thermal power plant Muzafargarh and Kot Addu Power Company (KAPCO), the former being located at smaller distance from Bahawalpur district. Finally, load trend of Bahawalpur district, optimum generation verses power demand, associated transmission losses, penalty factor and fuel cost economy are shown in the Results Section through graphs and tables. It is concluded that thermal power plant shares higher contribution of load power due to smaller distance from load and, thus, smaller transmission losses ensuring minimum cost operation.

Electromagnetic numerical studies of silicon and diamond microdisks coupled with silicon and diamond slab waveguides are performed in the CO2 laser emission region in the mid-infrared. Microdisk is the 2D analog of the microsphere and the slab waveguide is the 2D analog of the rectangular optical waveguide. The evanescent coupling between the waveguide and the microdisk results in efficient pumping of the whispering gallery modes of the microdisk. On-resonant and off-resonant studies are performed by tuning the laser wavelength to the microdisk whispering gallery modes. [ABSTRACT FROM AUTHOR]

This study is concerned with the development of some synthetic polymers, copolymers and their sulfonated derivatives as adsorbents. The effectiveness of these adsorbents in removing Cr(III) from aqueous solution was evaluated by batch technique. The influence of different experimental parameters on removal process such as solution pH, contact time, adsorbent dose, Cr(III) concentration and temperature were evaluated. Adsorption equilibrium was achieved in 20 to 30 min. at pH > 5. The Langmuir, Freundlich and Temkin adsorption isotherms were used to elucidate the observed sorption phenomena. The maximum Cr(III)37.8mg/gram of PS(polystyrene) and 37.2 mg/g of SAN (styrene/acrylonitrile copolymer) was removed as evaluated from Langmuir isotherm while the heat of sorption was in the range 0.21-7.65 kJ/mol as evaluated from Temkin isotherm. It can be concluded that PS developed in this study exhibited considerable adsorption potential for application in removal of Cr(III) from aqueous media as compared to its copolymers and other derivatives used in this study. [ABSTRACT FROM AUTHOR]