ANT Colony System Method to Vehicle Routing Problems

Authors: Amin Ahmadi; Ahmad Foroozantabar


Abstract

In this paper we want by use of ant Colony Optimization (ACO) that is one of the meta-heuristic methods that constructs solutions of hard combinatorial optimization problems. In this desertion, a suitable algorithm is presented to minimize logistic costs in supply chain downstream and in distribution network’s chain. Suggested algorithm is based on Ant Colony System and searched two goals with finding paths with the minimum number of vehicles and minimum time of costumers, service. This algorithm has been implemented on a distribution network company producing dairy products with 75 clients. Initially vehicle routing problem of this company has been solved with used nearest neighborhood heuristic algorithm And its result is compared with the proposed algorithm. The results show that the response of proposed algorithm is more efficient from the response of nearest neighborhood algorithm. The proposed algorithm is fully applicable and it has this capability that is implemented on the supply chain network in our country and thereby to achieve reducing supply chain logistic cost and ultimately reducing product’s final price.

Index Terms

colony optimization, Vehicle routing, Cyclic transfer, combinatorial optimization, Optimization.

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ANT Colony System Method to Vehicle Routing Problems

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Improvement in the Radial Distribution Primary System Design to Overcome Feeder Outage

Authors: El-zein and E. Safie El-din

Abstract

This paper studies the outage of the feeders branching from the distribution substation in a redial distribution system and introduces the required improvement in the system design to overcome the outage of any feeder and to achieve the continuity of supply to the consumers. Also, this paper calculates the increase in the cost to overcome the outage of a specified feeder and the increase in the cost to overcome the outage of any feeder branching from the substation. Finally, the paper discusses the probability of occurring each outage case and the corresponding number of consumers who get benefit from this design. The proposed algorithm is applied on two cases: The first case is 25 load points with a 20kv substation and the second case is 104 load points with a 11kv substation.

Index Terms

distribution planning , radial system, rural system, feeder outage, feeder reconfiguration

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Improvement in the Radial Distribution Primary System Design to Overcome Feeder Outage

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Optimal Coordination of Directional Overcurrent Relays using Hybrid PSO-DE Algorithm

Authors: Mohamed Zellagui , Almoataz Youssef Abdelaziz

Abstract 

This paper presents a new approach for the optimal coordination of IDMT directional overcurrent relays in meshed power systems using a hybrid particle swarm optimization based differential evolution algorithm (PSO-DE). In protection coordination problem the total operating time of all main relays is minimized. Constraints of the problem are; backup relay should operate if primary relay fails to respond the fault near to it, Time Dial Setting (TDS) and Plug Setting (PS) and minimum operating time of relay. The operating time of IDMT directional overcurrent relays holds non-linear relationship with TDS and PS. The proposed hybrid optimization algorithm is to minimize total operation time for each protection relay.  Two case studies are modeled and simulated to check the efficiency of the optimization algorithms such as IEEE 4-bus and IEEE 6-bus. The results are compared with the results obtained through other optimization algorithms. From the comparative results, it is found that the PSO-DE approach provides the most globally optimum solution at a faster convergence speed.

Index Terms 

Meshed Power Systems, Directional Overcurrent Protection, Optimal Coordination, Particle Swarm Optimization, Differential Evolution Algorithm, Hybrid Optimization Algorithms.

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Optimal Coordination of Directional Overcurrent Relays using Hybrid PSO-DE Algorithm

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Evaluation of Fault Diagnostic System for a Multistring Multilevel Inverter Using an Artificial Neural Network

Authors: C.Dinakaran

Abstract

 In recent years, the demand for higher power ratings for industries has increased and multilevel inverter system has become a solution for high power applications. A multi level inverter system not only achieves high power ratings but also implement the use of renewable energy sources. As multilevel inverter systems are utilized in high power applications and reliability of the power electronics equipment. For example, industrial applications such as manufacturing industries are dependent upon induction motors and their inverter systems for manufacturing process control. In general, the conventional protection systems are passive devices such as fuses, overload relays and circuit breakers to protect the inverter system. Whenever a fault occurs, the protective devices will disconnect power sources from multilevel inverter system. Downtime of manufacturing equipment results in huge loss. Many engineers and researchers have focused on incipient fault detection and preventive maintenance to avoid inverter and motor faults. The most important factor is to operate the system continuously during   abnormal conditions. In order to maintain continuous operation for a multilevel inverter system, knowledge of fault behavior, fault prediction and fault diagnosis are necessary. Faults should be detected as soon as possible after they occur, because if a motor drive runs continuously under abnormal conditions, the drive or motor may quickly fail. In this paper a fault diagnostic system in a multilevel- inverter using neural network is developed. The performance of proposed system is verified by MATLAB/SIMULINK, PROTEUS software and Hardware setup.

Index Terms

Diagnostic system, Fault Diagnosis, Multi string multilevel inverter, Artificial Neural Network.

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Evaluation of Fault Diagnostic System for a Multistring Multilevel Inverter Using an Artificial Neural Network

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Synchronized Reactive Power Compensation in a Microgrid System Using FOPID Voltage Regulator

Abstract 

Distributed generators connected to the grid, when operating in parallel, the load sharing among them without affecting the security and reliability is a crucial issue. In such a large interconnected system it is necessary to have communication among the DG’s for effective load sharing which otherwise will influence the security of the grid. The paper concerns with a strategy for real and reactive power sharing independently based on the locally measured signals without having communication between the DG’s. A Fractional order Proportional Integral Derivative (FOPID) based control strategy was proposed to determine the power control error and to control the parameters of DG’s for effective load sharing between them. The proposed strategy was implemented with three DG’s feeding linear loads and was realized in MATLAB / SIMULINK platform. The simulation results depict an improved dynamic performance with fractional order PID controller over the conventional PI controller.

Index Terms

Distributed generation (DG), Droop control, Reactive power compensation, Power sharing, Fractional Order PID controller.

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Synchronized Reactive Power Compensation in a Microgrid System Using FOPID Voltage Regulator

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Mitigation of Lightning Hazards at the More Sensitive Points in Wind Farms Using Ant-Colony Optimization Technique

Authors: M. A. Abd-Allah, A. Said, Mahmoud N. Ali

Abstract

The lightning energy can be very harmfull to the wind turbine farm components. This paper attempts to evaluate the over voltages at the sensitive points in wind farm, using ATP-EMTP package program. Four cases were performed; a) the transient voltage distribution in the insulating layer of the control line, b) the transient voltage on the control equipment, c) the coupling voltage between the tower and the control, and, d) the transient voltage distribution in the wind turbine WT Generator, Boast transformers and grid. These cases were performed under different lightning current conditions and at conventional design and proper design of grounding system. The results show that the Ground Potential Rise (GPR) is reduced with using the proper design of wind turbine ground system, but the induced voltage at the control system will not affected. This work determines the optimum location of wind turbine at the areas of maximum lightning incidence. Ant Colony Optimization (ACO) technique is implemented to find the optimum wind farm location. This work enhances the protection strategy of the wind farms against lightning stroke.

Index Terms

Overvoltages, GPR, Capacitive coupling, ATP-EMTP, WT Generator, ACO

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Mitigation of Lightning Hazards at the More Sensitive Points in Wind Farms  Using Ant-Colony Optimization Technique

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HGAPSO based Method for Solving Unit Commitment Problem

Authors: Mohammad Reza Salimian, Mohammad Taghi Ameli

Abstract

The production cost of generators could be minimized by optimizing the schedule of generation. Unit commitment problem is used for scheduling the generation. In this paper, Hybrid genetic Algorithm and PSO (HGAPSO) is used for solving unit commitment problem. In fitness function, all constraints of unit commitment problem are satisfied without using penalty function. The proposed method is tested on ten generator test system. At the end, the results obtained from HGAPSO are compared with the results of other methods.

Index Terms

Unit Commitment, Hybrid genetic Algorithm and PSO, Optimization, Production Cost

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HGAPSO based Method for Solving Unit Commitment Problem

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Global Solar Energy: A Review

Authors: Ashish Kumar Singhal , Neha Yadav,N.S. Beniwal


Abstract

As view of recent trend in Electricity, Our world is facing the problem in electricity due to lacking of fossil fuels. We need to reduce greenhouse gasses emission, have made renewable resources attractive in world energy based economies. The potential for renewable energy resources is enormous. In principle, exponentially exceed the world’s energy demand. Therefore, these types of resources will have a great development in the future global energy portfolio, much of which is now concentrating on advancing their pool of solar energy resources. This paper presents how solar energy is currently used in across the globe.

Index Terms

Solar energy, their type, demands of energy in the world and their availability

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Global Solar Energy: A Review

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A Novel Phase Shifted DC-DC Converter with Adaptive Soft Switching to Improve Efficiency under wide Load Range

Authors: Sudha Bansal,   Lalit Mohan Saini


Abstract

This paper presents a novel dc-dc converter with adaptive soft switching as a means to achieve ZVS operation for all the switches. It adopts phase shift modulation features for constant frequency operation and adaptive soft switching at low load. To accomplish this task two loops are employed; inner current control loop is to check the loading condition and turn on of auxiliary switch accordingly. Outer control loop is used to improve the dynamic performance of DC-DC converter by achieving a robust output voltage against load disturbances. This paper also presents the performance of various controllers. A 1kW/100KHz dc/dc converter is simulated and analyzed. Performance of the proposed topology is evaluated at different loads i.e. static and dynamic load (DC motor). An efficiency comparison of the converter with a reported topology has also been carried out.

Index Terms

DC-DC converter, phase-shifted, resonant tank; reverse recovery, resonant converter, Soft switching

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A Novel Phase Shifted DC-DC Converter with Adaptive Soft Switching to Improve Efficiency under wide Load Range 

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Reference Signal Limiter in the Control of Buck Power Converters with Improved Stability

Authors: Prasanth Sai, M. Narendra Kumar, S. Sunisith

Abstract

This paper presents the solution for controlling the dc-dc switched power of Buck type converter. This technique states that the control signal can take the values in the range (0, 1) only. Such a control limitation is generally not considered into account when designing the converter regulators. This is only dealt with in the control implementation stage, placing a limiter (controls the range of input signal) between the controller and the controlled system. In this, the control signal limitation is provided by using a non-linear regulator that consists of an internal limiter. The final closed-loop control system is nothing but the non-linear feedback involving a linear dynamics block in closed-loop with a non-linear static element. If these conditions are satisfied when choosing the control design parameters then the regulator improves closed-loop stability and output reference tracking.

Index Terms

Buck Converters, Reference Signal Limiter, Switched Power Converter.

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Reference Signal Limiter in the Control of Buck Power Converters with Improved Stability

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