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As high voltage DC power system is gaining popularity, power electronic switching devices are becoming increasingly advanced to overcome problems of timely fault isolation. In this context, hybrid DC circuit breakers (DCHCBs), especially, together with wideband gap-based semiconductor devices, play a crucial role to tackle the current and voltage at high power and frequency. In this paper, a hybrid DC circuit breaker is designed leading to development of a fault interruption scheme for HVDC power system, as in HVDC system, fault interruption is considered more critical compared to the conventional high voltage AC (HVAC) power system. The proposed design of hybrid circuit breaker (HCB) involves combination of mechanical and electronic switches for efficient fault interruption. The mechanical part is covered by using vacuum circuit breaker (VCB) and the electronic switching part involves use of SiC-MESFET as these are more powerful and fast switching elements. For the fault interruption schemes to be valid, artificial current zero is created using current commutation. The system model is designed using Simulink and comparisons are carried out between the proposed hybrid scheme and the recent fault interruption schemes in terms of power loss and fault clearing time. The results of the proposed design are measured in terms of system current, commutation current and voltage across the commutation capacitor.

The term smart grid (SG) allows optimizing energy efficiency by flexible interconnection of central and distributed generators (DG) through transmission and distribution system to industrial and consumer end-users. In near future it is predicted that Distributed Generation (DG) from renewable energy resources (RES) will play a massive role to fulfill the users need and enhance the efficiency of smart grid. The increasing use of switching applications in SG integrated with RES may cause power quality problems in the term of harmonics pollution in the distribution systems. This paper proposes the designing and use of LLCL filter to mitigate the effect of harmonics in smart grids. The performance of the suggested method is checked by the simulation results using ETAP (Electrical Transient and Analyzer Program) and MATLAB (Matrix Laboratory). Theoretical analysis has been done using Simulation and real time data results of Sapphire Textile Industry unit-3.

Now a days, Fuel Efficiency and minimum pollution in vehicles is a major research area. Solar Hybrid vehicles are becoming popular because they are fuel economical and able to provide power and speed upon need without any charging limitations. But the major setback in them is their prolong charging time. Hybrid technology-based automobiles are getting increased attention which results in their increased cost. Due to this, it is almost impossible for a common consumer to afford it. The work presented here; throws light on the employment of solar hybrid electric vehicle technology on a regular gasoline motorbike. The implementation of solar hybrid electric technology on the motorbike is done in a modified parallel hybrid configuration. Motorbike efficiency is to be improved by emphasis on electrical part and its development. This research, discusses all the phases from designing to construction and implementation of this technology on the motorbike.

The sole purpose of this research work is to inspect effectively the tradeoff relation between the cost of electricity and consumer satisfaction level. Variation in power demand in day ahead with forecasting studies for the low cost and cheap energy procurement (CEP) and unplanned recognition of actual time renewable power develops difficulties for the intelligent energy management system (IEMS) to meet the satisfaction level of the customers. For the AC/DC hybrid system, where losses are observed in the convertor and invertor during AC to DC and then from DC to AC conversion respectively, the problem becomes more complex. In the same manner, the stats of peak hours show the requirement of increasing generation power in order to fulfill the peak load demand which is bought at very much higher rates by the power producer companies. This work will give the optimization technique of problem solving for minimizing such issue for the average time cost of power for the utmost satisfaction level of the consumer. The proposed solution will be achieved by introducing the algorithm of Load Scheduling and Hybrid Switching Control (LSHSC) on the framework of convex optimization. This results in the delivering of efficiently low-cost electricity with assisting shift-able loads within the convinced time limit.The intelligent energy management system (IEMS) usually installed near the consumer along with distributed generators. The substantial part depends on the continuously monitoring and at the same time monitoring and controlling the flow of power between power producing utilities and consumers through hybrid AC/DC bus system. A large convertor and invertor losses are being incorporated in this system.

The flexibility of a transformer enables it to have a wide range of applications. One of the most important parameters that has an influence on the transformer insulation is the temperature. Hence, the parameter to be controlled is the fan speed and flow rate of oil (using pumps) that varies invariantly with the load. The conventional control technique which is winding Temperature Indicator (WTI) fails to achieve this task. The mechanism for Cooling of power transformer is designed on the process of measuring top-oil temperature along-with a simulation used to find the point of highest temperature in the winding. WTI has some short-comings and researchers now prefer the presentation of fiber optic based temperature sensors for this critical function. Fiber optic sensors have been selected for the control of the cooling banks. The long-term performance of transformer cooling can be better achieved with these more accurate and modern fiber optic sensors. This paper presents a mechanism to control the temperature of power transformer using smart cooling system which includes Forced Oil (FO) pumps and fans. A comparative analysis is also performed between the WTI system and the proposed smart cooling system. Flow control of these cooling devices is controlled and monitored by the use of PID-controller via traditional Ziegler-Nichols algorithm and advanced Ziegler-Nichols algorithm organized with fresh developments in sensor technologies. This regulator pushes the designed system to operate in flow and temperature regimes which limit the problem of minimizing thermal degradation of the insulation.

Now a days HVDC Transmission System are being used due to its advantage over HVAC Transmission systems based on several features like minor Transmission losses, efficient control of Electric power flow, stability and very economical for long Transmission lines. Transmission Line having length of several kilometers and located in open environment for this fault occurring chances are very high as compared other part of power system. These faults have several effects, its necessary to detect and classified these faults within very short time for safe operation of power system. This paper presents the solution of fault detection and classification of overhead HVDC Transmission lines by applying Discrete Wavelet Transform (DWT). Faults in HVDC Transmission line of several types have been created using MATLAB/Simulink. The current signals of HVDC Transmission Lines are attained from Current Transformer and Scope block in work space, and then decompose by means of DWT to obtain the details coefficients up to three levels. Furthermore, Norm of detail coefficient at 3rd level is calculated. To detect and Classification the faults on HVDC Transmission lines Value of Norm are compared with threshold values of the system. The proposed approach has been successfully tested for various types of faults at different line location.

This paper deals with the interruption scheme designed using Vacuum Circuit Breaker (VCB) based on zero crossing characteristics, implemented electromechanically for High Voltage Direct Current (HVDC) system. The operation is carried out using Mechanical scheme as it has minimum energy loss in comparison to Solid-State and Hybrid schemes. The Mechanical scheme consists of series connection of multiple modules, variable resistors, VCB, and RC snubber circuit. The commutation is performed through a commutation branch that consists of LC circuitry and a switch. An inverse current is injected in the system through commutation branch at the instant of fault occurrence to interrupt the arcing process. MATLAB is used for designing the simulation of the proposed scheme. The results of the simulation are analyzed and improvements from previous schemes are discussed.