Improving the Transient Frequency Response of Rich-Generation Islands via Optimal Control

Authors:A. S. Elzawawy, A. H. Yakout, W. M. Mansour, F. M. Bendary

 

Abstract

This paper presents Genetic Algorithm (GA) optimization technique as a tool for tuning PID Load Frequency Control LFC. This is to ensure the sustainability of the formed islands after uncontrollable system separation. A two-area single-reheat tandem-compound thermal system is considered. It is focused on an island with excess generation to be equipped with local PID-LFC. The PID controller uses Genetic Algorithm (GA) to obtain the values of PID controller parameters. PID controller parameters are tuned off-line to minimize integral square error over a wide-range of interrupted power. The PID controller is tuned by Ziegler-Nichols method in order to demonstrate the superior efficiency of the proposed (GA) in tuning the PID controller. Therefore, the proposed technique could tune the PID controller for optimal response at any value of the interrupted power. Testing of the developed technique shows that, the proposed PID-LFC could present optimal performance and it capable of improving the transient frequency response of thermal power plants. So it contributes in improving the overall area response. Results are provided in the form of time domain simulations via MATLAB /SIMULINK.

 

Index Terms

Islanding, blackout, auxiliary governor, Load Frequency Control (LFC), PID controller, Genetic Algorithm.

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Improving the Transient Frequency Response of Rich-Generation Islands via Optimal Control

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Superiority of LVRT of Grid Connected Wind Energy Conversion System Using Unified Power Quality Controller

Authors:M. N. Eskander, M.A.Saleh, Maged N.F.Nashed, S. Amer

Abstract

The Unified Power Quality Controller (UPQC) device is  an  integration of a series active filter and a shunt active filter. The main purpose of a UPQC is to compensate for voltage flicker, reactive power, and harmonics. It has the capability of improving power quality at the point of installation on power distribution systems or industrial power systems.

This paper utilizes the UPQC to enhance the low-voltage ride-through (LVRT) capability of the doubly fed induction generator (DFIG)-based wind energy conversion system (WECS) according to the grid connection requirement. UPQC is applied to protect the system from ground faults, allows fast restoring of generation system steady state characteristics, improves the system power factor, and prevent the system from rotor over-current and dc-link overvoltage. A comparison between the LVRT results using the UPQC and the results when using STATCOM or DVR is also presented.

 

Index Terms

Unified Power Quality Controller, doubly fed induction generator, low-voltage ride-through, static synchronous compensators, dynamic voltage restorers, MATLAB/Simulink

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Superiority of LVRT of Grid Connected Wind Energy Conversion System Using Unified Power Quality Controller

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Grid Connection and Islanding Operation of Distributed Generation with Synchronous Frame Controller

Authors: L.Vamsi Narasimha Rao , S.N.V.S.K.Chaitanya

Abstract

Renewable energy resources (RES) are being increasingly connected in distribution systems utilizing power electronic converters. This paper presents a novel control strategy for the synchronous frame control also called DQ control, uses reference frame transformation module eg: abc to dq to transform the grid current and grid voltage waveforms into a reference frame that rotates synchronously with grid voltage. By means of this, the control variable becomes dc values then filtering and controlling can be achieved. This paper also deals with islanding operation which activates when the voltage and frequency of the grid exceeds the specified value at the point of common coupling. Thus potency of the technique is illustrated using MATLAB Simulation.

 

Index Terms

Phase Locked Loop, Photo voltaic cell, PEM fuel cell, Synchronous frame controller, MATLAB/Simulation

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Grid Connection and Islanding Operation of Distributed Generation with Synchronous Frame Controller

 

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A Novel DC-Side Current Injection Technique for 18-Pulse Converter System to Improve AC Line Condition

 Authors: N. Venkata Ramana and V. L. N. Sastry


Abstract

In this paper, a new compensation strategy for receiving clean power of a conventional 18-pulse ac/dc converter formed by three 6-diode bridges is proposed. According to the proposed strategy, a three-phase current-controlled inverter injects the compensation currents into the three positive terminals of the three six-diode bridges. The goal of injecting currents at dc side is to improve the quality of the ac line currents. Compared to the conventional active filter deployed at the ac side, the three-phase inverter used in this paper is with lower KVA rating, and the 18-pulse converter draws nearly sinusoidal currents from the ac main by the proposed compensation strategy. The simulation results demonstrate that the proposed method improves the line current quality.

Index Terms

Current-controlled inverter, inter phase trans-former (IPT), multi pulse transformer, total harmonic distortion, 18-pulse converter.

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A Novel DC-Side Current Injection Technique for 18-Pulse Converter System to Improve AC Line Condition

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Unit Commitment with Economic Dispatch

Authors:  M.S.Krishnarayalu

Abstract

Economic Dispatch (ED) in power systems is very important as it saves lot of money. There are two basic methods available. One is classical method where all units are committed and consumption of fuel is optimized by an optimization method. Second one is Unit Commitment (UC) method. In UC, units are committed based on their efficiency order and on load demand with most efficient unit committed first. Now a method called Unit Commitment with Economic Dispatch (UCED) is proposed combining these two methods. The efficacy of this new method is illustrated via a three unit thermal plant system.

Index Terms

 Fuel cost, Optimization, Economic Dispatch, Unit Commitment

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Unit Commitment with Economic Dispatch

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Hybrid Power Generation Systems:A Holistic View

Authors: S. F. Mekhamer, A. Y. Abdelaziz, M.A.L. Badr, M. A. Algabalawy

Abstract

The importance of the hybrid power generation systems (HPGS) increased especially in the last few years. HPGS are used to share the load with the utility grid and these systems are termed as HPGS-utility grid. In addition, they are used to transmit the power to the remote areas. In this case, these systems are termed as stand-alone HPGS.

HPGS consist of different power sources such as photovoltaic systems (PV), wind turbine (WT), micro-turbine (MT), storage battery (SB), diesel generator, and fuel cell (FC). These sources are considered the prominent elements. The importance of the HPGS can be carried out via classifying these systems based on their combinations.

This paper gives a literature survey for different combinations of HPGS that consist of different combinations of PV, WT, SB MT, diesel generator, and Fuel Cell.

 

Index Terms

Hybrid power generation, PV, wind turbine, fuel cell, battery bank, and standalone power source.

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Hybrid Power Generation Systems:A Holistic View

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Grid Connected Single-Phase Bidirectional Inverter with MPPT Tracker

Authors: M.Srikanth, S. Tarakalyani, Poonam Upadhyay

Abstract

This study is focused on Grid Connected Single-Phase Bidirectional Inverter with Boost Maximum Power Point Tracker (MPPT). By using PV system and a DC-DC boost converter with MPPT generate power that power utilized by the dc applications .Whenever surplus power is available that power sell to grid, When sun intensity is in bad condition we can buy the power from a grid, a bidirectional inverter is required to control the power flow between dc bus and ac grid. It also proposes (MPPT) algorithm is used to track the maximum power of PV cell. In this grid connected inverter, inverter can be operated with pulse switching and unipolar PWM switching and a suitable LC filters. Simulation results show that the model can effectively realize the actual physical characteristics of a Grid Connected Single-Phase Bidirectional Inverter with Boost Maximum Power Point Tracker (MPPT).

Index Terms

Photovoltaic system, MPPT, boost converter, bidirectional inverter, grid-connection and unipolar PWM switching.

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Grid Connected Single-Phase Bidirectional Inverter with MPPT Tracker

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Active Power Control of Grid Connected Hybrid Fuel Cell & Solar Power Plant

Authors: Kapil Dev Sharma, Sumit Saroha, Sunil Kumar


Abstract

The interconnection of both conventional and non conventional energy sources with grid is an important aspect of power system to meet the growing demand of electricity in present day scenario. This paper proposed a Solar PV array system with and without grid interconnected in which the Maximum Power Point Tracking algorithm is used for extracting maximum available power from PV module. Two operating control modes unit-power control (UPC) mode and feeder-flow control (FFC) mode has been considered. In UPC mode load variations are compensated by the main grid because the hybrid source output is regulated to reference power. Whereas in FFC mode the feeder flow is regulated to a constant, the extra load demand is picked up by the hybrid source. The purposes of the proposed operating strategy presented are to determine the control mode, to minimize the number of mode changes, to operate PV at the maximum power point, and to operate the FC output in its high-efficiency performance band. It is found that the proposed operating algorithm is a simplified and flexible method to operate a hybrid source in a grid-connected micro grid.

 

Index Terms

Fuel cell, Solar power, Micro grid, Unit power control (UPC), Maximum Power tracking algorithm.

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Active Power Control of Grid Connected Hybrid Fuel Cell & Solar Power Plant 

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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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