International Journal of Applied Power Engineering (IJAPE)
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Optimization of Economic Load Dispatch with Unit Commitment on Multi Machine
Get PDFEconomic load dispatch (ELD) and Unit Commitment (UC) are significant research applications in power systems that optimize the total production cost of the predicted load demand. The UC problem determines a turn-on and turn-off schedule for a given combination of generating units, thus satisfying a set of dynamic operational constraints. ELD optimizes the operation cost for all scheduled generating units with respect to the load demands of customers. The first phase in this project is to economically schedule the distribution of generating units using Gauss seidal and the second phase is to determine optimal load distribution for the scheduled units using dynamic programming method is applied to select and choose the combination of generating units that commit and de-commit during each hour. These precommitted schedules are optimized by dynamic programming method thus producing a global optimum solution with feasible and effective solution quality, minimal cost and time and higher precision. The effectiveness of the proposed techniques is investigated on two test systems consisting of five generating units and the experiments are carried out using MATLAB R2010b software. Experimental results prove that the proposed method is capable of yielding higher quality solution including mathematical simplicity, fast convergence, diversity maintenance, robustness and scalability for the complex ELD-UC problem
Analysis of Solar Radiation Availability for Deployment of Solar Photovoltaic (PV) Technology in a Tropical City
Get PDFThe sunshine hours and solar radiation data for Ibadan (7° 30´ N, 3° 54´ E.), South West Nigeria in the last twenty years was analyzed, with a view to determining the abundance of solar energy available for deployment of solar photovoltaic (PV) technology applications. The measured solar radiation and actual sunshine hour data were obtained from International Institute of Tropical Agriculture (IITA), Ibadan. The data were analyzed using the statistical package of „origin 7‟ software. The maximum of 16.1MJm-2day-1 and minimum of 10.71MJm-2day-1 occurred in months of May and August respectively while the actual sunshine hour variation follows the same general trend but with the maximum of 6.99hrs in February and a minimum of 2.37hrs in August. At the current solar-to-electric conversion efficiency of 10%, the minimum solar radiation of 10.71MJm-2day-1 can supply a 1.0m2 solar panel a minimum of 44.6KWhr of Energy. Thus an abundance of solar energy has been established at Ibadan which in recent times has been witnessing incessant power outages from the national grid and thereby can contribute significantly to efforts in improving power supply mix. This implies that solar energy technology can thrive not only at Ibadan but in the whole of South West of Nigeria. Evidence of viability of PV technology in this area also abounds in the success of Solar Water Pumping stations recently installed by Government Agencies such as Ogun-Osun River Basin Development Authority (ORBDA) and the Millennium Development Goal (MDG) programmes in the area and environs
Impact of FACTS Devices in Optimal Generation in Deregulated Power System
Get PDFSince Gencos and Discos compete primarily based on the price in a deregulated market, minimizing the losses or regulating the voltage or controlling the power flow within the rating of power system components such as cables, transformers, transmission lines become extremely difficult. Recent developments in FACTS devices increases the number of constraints and nonlinearity, and henceachieving the optimal solution becomes further complicated. The Optimal Power Flow Problem, determines the best way to operate a power system at any given instant. It solves the power system load flow with an aim to optimize system operating conditions while automatically adjusting control variable settings without violating the system operating constraints. In this paper such constraints based OPF scheme is developed and presented which also incorporates various Flexible AC Transmission Devices. In this work three different types of FACTS devices namely SVC, TCSC, UPFC are separately included into the OPF problem in addition to the conventional constraints that govern an OPF solution. An IEEE 30 bus system is considered and the results obtained for three different loading conditions with three different FACTS devices and their performance are evaluated
Design of Distributed Generation with A Hybrid System in Karimunjawa Island
Get PDFThe current condition, in Karimunjawa Island, is supplied by diesel power with a total power output of 400kW. The number of households in this island is 1545, while the number of electricity customers as many as 850 homes with the local electrification ratio of 55%. With such high load electrification, the generator is only operated from 05.00pm-06.00pm every day to limit the operating costs. Methodology used was the determination of the size of the PV generator capacity based on the percentage of daily generation. The selection of conversion technology with hybrid concept synergizes photovoltaic to be combined with diesel. Loading simulations are performed with HOMER application that provides a variety of features on a variety of configurations and scenarios designed.The first scenario is in the form of giving additional capacity by using the power of 100kW of PV system and at peak load by adding the duration of the day with 5 hours, it is obtained the production of PV of 800kWh/day with the selling price of $ 3,900;/kWh. The second scenario is in the form of giving additional capacity by using the power of 100kW of PV system at noon for 10 hours and during peak load, it gains total value production of PV with1400kWh/day and distributed to system with a selling price of Rp 3,867/kWh
Investigation of Dependent Rikitake System to Initiation Point
Get PDFIn this paper we investigate depending of the Rikitake system to initiation point, and monitor changing behavior of this system. We will have 4 initiation points in Cartesian system. We at 4 positions, will monitor behavior of this system, while holding constant other values, and after per position, will draw operation of system on axes of x, y, z and 3-D plot. We want to know, what is the effect of initiation point on Rikitake system? Numerical simulations to illustrate the effect of initiation point are presented, and at the end conclusions and comparing the states together are obtained
Predictive Control Fed by An Indirect Converter With and Without Energy Storage Using PSO Optimization
Get PDFThe paper presents an improved predictive direct control of a variable speed. The method is based on finite states space model of the converter. The proposed control method selects the optimal switching state of (Indirect Converter with and without energy storage for rectified and inverter) that minimizes the error between orthogonal torque, fluxs, and the reactive power components predictions to their computed values for all different voltage vectors. The optimal voltage vector that minimizes a cost function is then applied to the output of the power converter. The main aim of this paper is to propose an online optimization of the weighting factors by the Particle Swarm Optimization (PSO) approach well known by its robustness and fast convergence to the global optimum. Simulation results show that PSO strategy is very efficient to design accurately and quickly these weighting factors
Harmonic Voltage Distortions in Power Systems Due to Non Linear Loads
Get PDFHarmonics are found to have deleterious effects on power system equipments including transformers, capacitor banks, rotating machines, switchgears and protective relays. Transformers, motors and switchgears may experience increased losses and excessive heating. Shunt filters are effective in minimizing voltage distortions. This paper describes the voltage distortions generated by non linear loads. The harmonic specifications such as harmonic factor, characteristic harmonic and non-characteristic harmonic are considered while explaining the paper. ‘MiPower’ software is used to compute the harmonic distortions in a sample power system. Accurate harmonic models are established for a non linear load. To reduce the harmonic voltages impressed upon specific parts of the sample power system, passive filters are installed at two buses. With the implementation of a passive filter at the bus with non linear load, the harmonics are greatly reduced. For the specified power system, at all the buses the total harmonic distortion has been evaluated
Investigation of Electric Field Distribution Inside 500/220 kV Transformation Substations during Different Working Conditions
Get PDFThis study depicts the electric field distributions inside a typical 500/220 kV open distribution substation under actual loading conditions and during different working conditions, Hot-Stick position and Bar-Hand position. The electric field is investigated for different workers heights of 1m, 1.5m and 1.8m above ground during normal working condition (Hot-Stick position) inside this substation. This in addition to assessment of the electric field at a height levels of 8m, 11m, 14m and 17m above ground as positions for live line maintenance under 220 kV Busbars, 500 kV Busbars, 220 kV Incoming and Outgoing feeders and 500 kV Incoming and Outgoing feeders respectively. In this study the simulation results of the electric field obtained using three dimensional (3D) computer model for existing typical high voltage transformation substation are compared with field values measured inside this typical substation and presented and discussed not only in the form of contour maps but also in the form 3D surface and wireframe maps. The simulation results are good matched and agreed with measured values. This in addition to the electric field will be tabulated and compared to international guidelines for personnel exposure to electric field. This study will serve for planning service works or for inspection of equipment inside high voltage (HV) power transformation substations
Comparison of FACTS Devices for Two Area Power System Stability Enhancement using MATLAB Modelling
Get PDFModern Power Transmission networks are becoming increasingly stressed due to growing demand and restrictions on building new lines. Losing stability is one of the major threat of such a stressed system following a disturbance. Flexible ac transmission system (FACTS) devices are found to be very effective in a transmission network for better utilization of its existing facilities without sacrificing the desired stability margin. The static synchronous compensator (STATCOM) and Static Var Compensator (SVC) are the shunt devices of the flexible AC transmission systems (FACTS) family. When system voltage is low, STATCOM generates reactive power and when system voltage is high it absorbs reactive power whereas the Static Var compensator provides the fast acting dynamic compensation in case of severe faults. In this Paper, the performance of SVC is compared with the performance of STATCOM. Proposed controllers are implemented using MATLAB/SIMULINK. Simulation results indicate that the STATCOM controller installed with two machine systems provides better damping characteristics in rotor angle as compared to two machine system installed with SVC. Thus, transient stability enhancement of the two machine system installed with STATCOM is better than that installed with SVC
A Survey on Quality Changes in Positive, Negative and Combined Switching Strategies in Control of Three Phase Matrix Converter
Get PDFIn this paper uses positive, negative and combined switching strategies for three phase ac/ac matrix converter .the author compares these strategies. The performance comparison of these three strategies is made under balanced operation. The simulation of three phase matrix converter feeding a three phase load was accomplished by means of the matlab/simulink software. After the simulation the comparison of the waveforms THD in three switching sequence is done. It must be mentioned that the duty cycle of the whole switches in the converter is according to Venturini switching algorith