Applied Mechanics and Materials Vol. 573

Abstract: – The unified power flow controller (UPFC) is the most versatile and complex power electronic equipment that has emerged as the indispensable equipment for the control and optimization of power flow in electrical power transmission system. In this manuscript is investigated the control of real and reactive power flow through a transmission line with the use of UPFC at the sending end. Computer simulation using MATLAB Simulink is done and the behavior of the UPFC is studied. In the UPFC based control of transmission line parameter control systems, it is observed that whenever the SSSC sources some real power into the transmission line it is manifested as a voltage drop across the DC link. Reactive power demand is indicated as fall in the bus bar AC voltage. The fall of the DC link voltage is an indication of real power demand from the receiving end. Similarly a fall of the bus bar AC voltage is an indication of reactive power demand from the receiving end. Fuzzy Logic and PI controllers are used in this works, the control of DC voltage, AC voltage and power transfer.

Abstract: This paper presents an estimator for a nonlinear active suspension system considering the hydraulic actuator dynamics. PID controller is used to control the Active suspension system of nonlinear quarter car model. Extended Kalman filter is designed to estimate the states from the measurement model perturbed with noise. Simulation results demonstrate the effectiveness of the PID based active suspension system in reducing the vertical acceleration transmitted to the passengers thereby improving the ride comfort. Also the effectiveness of the Extended Kalman filter in estimating the actual vehicle states is demonstrated.

Abstract: In this paper, Genetic Algorithm (GA) method has been applied in the moisture control system for auto tuning (PID) parameters. Proportional – Integral – Derivatives control scheme is used to provide an efficient and quiet easier in control engineering applications. Most of the PID tuning methods are used as manually which is difficult and time consuming. Genetic Algorithm which leads to improve the efficiency of tuning of process. The proposed algorithm is used to tune the PID parameters and its performance has been compared with Fuzzy logic techniques.Compare to the fuzzy logic technique dynamic performance specfications such as rise time, peak time and peak overshoot optimal values produced by GA. The plant model represented by the transfer function is obtained by the system identification tool box.

Abstract: This paper deals with the design and evaluation of robust excitation controller for a single-machine infinite-bus power system. The design of the regulator guarantees the stability of the closed loop system and ensures the output voltage is maintained within an acceptable threshold. In addition, it damps out local mode oscillations for small signal disturbances. The designed robust controller is also analyzed under change in step input and disturbance, which limits the heavy oscillations on the speed ω and voltage. Glover-McFarlane loop shaping algorithm is applied in designing the robust excitation controller. Two different techniques such as Optimal control and mixed sensitivity approach is used in this paper. The performance of the AVR was analyzed and compared with IEEE type2 Exciter.

Abstract: Abstract. This paper proposes a Power Management System (PMS) designed to supply continuous power for residential using low voltage Microgrid. The Microgrid equipped with a hybrid power supply includes, battery storage system and three power supplies: a wind mill, photovoltaic (PV) emulator and proton exchange membrane (PEM) fuel cell (FC). The connections of the energy resources to the common ac bus make use of power inverters with specific functionalities. The automatic power management system for the operation and control of the distributed energy resources connected to residential electric power installations, taking into account both the grid connected operating mode and the islanded operating mode. The PMS provides rapid response to support the critical load. It can also operate as a standalone system in case of grid failure like an incessant power supply. The operating behavior of the proposed automatic system is simulated by using MATLAB SIMULINK.

Abstract: Abstract. This paper discusses about the available transfer capability by using Unified Power Flow Controller-UPFC. Flexible AC Transmission System-FACTS devices helps to reduce power flow on overloaded lines, thereby increasing the loadability of the power system, transient stability, damp out oscillations and also provide security and efficient transmission system. UPFC is one of the most versatile FACTS controllers. It is used for both shunt and series compensation. Newton Raphson method is used to calculate load flow for IEEE 30 bus system. By optimally placing the FACTS device Available Transfer Capability-ATC is improved. The ATC is calculated by using AC Power Transfer Distribution Factor- ACPTDF and this method is based on the sensitivity approach. Imperialistic Competitive Algorithm (ICA) is used to find optimal location of placing UPFC to improve ATC.

Abstract: A Recent concept of distribution infrastructure plays a vital role in the efficient utilization of energy. To avoid global warming and greenhouse gas emission, carbon based power plant should be replaced with distributed renewable energy (DRE) such as wind, solar etc. Renewable energy resources can be integrated to grid by intelligent electronic devices (IED). This paper deals with the novel automation architecture that supports power distribution systems to avoid power blackout and also it briefs the major requirement of the smart grid distribution system needed for a competitive world. International standard IEC 61850 and IEC 61499 provides a solution for substation automation through intelligent logical nodes (ILNs) which enhances interoperability and configurability.Later an open source platform is used for enhancing the communication that automatically generates the data model and communication nodes for intelligent electronic devices.However for future requirements in smart grid, the addition of new functions as well as the adaptation of function for IEDs is necessary. A concept of reconfigurable software architecture is introduced for integrating distributed and renewable energy resources. Such interfaces and services provide adaptation of the functional structure and contribute efficient Smart Grid system. This survey summarizes the communication infrastructure of smart energy system.

Abstract: A power system structure has the generation, transmission and the distribution systems. During the transfer of power from the generation system to the distribution system, transmission line losses are occurred. To reduce the losses and keep the system stable, many controllers are being used. The Flexible AC Transmission systems (FACTS) are the modern controllers finding application in the power systems. The Unified Power Flow Controller (UPFC) is considered to be the best among the FACTS devices. It is installed in the transmission line to maintain the voltage of the system within the prescribe limits. The location to fix the UPFC is found using Shuffled Leap Frog Algorithm (SLFA). The transformer ratio is varied from its nominal value. Testing is done using an IEEE 30 bus system and the results are discussed.

Abstract: This paper presents a Dynamic Voltage Restorer to mitigate power quality disturbances such as voltage sag, swell and harmonics. The compensation strategy is based on pre-sag compensation. Controller based on dq0 transformation technique and ANN is implemented in order to maintain the nominal load voltage and phase angle. Simulation studies under three phase rectifier with parallel resistive/capacitive dc load as a non linear load is carried out. Also the system is investigated under voltage sag and swells on source side using programmable AC source. Simulation results show that DVR performs accurately in mitigating disturbances with minimum Total Harmonic Distortion. The performance of DVR is verified using Matlab / Simulink Environment.

Abstract: Parallel machine shop scheduling problem can be stated as finding a schedule for a general task graph to execute on a customed flow so that the schedule length can be minimized. Parallel Flow Shop Scheduling with a case study has been . In this study we present an effective memetic algorithm to solve the problem. Also evaluating the performance of two algorithms (genetic algorithm and memetic algorithm) in terms of both the quality of the solutions produced and the efficiency. These results demonstrate that the memetic algorithm produces better and quality solutions and hence it is very efficient . KEY WORDS: Hybrid Flow Shop Scheduling, Multiprocessor, Memetic algorithm.