CONTROL STRATEGIES FOR DGS TO IMPROVE OPERATION PERFORMANCE OF MICROGRID

Title
CONTROL STRATEGIES FOR DGS TO IMPROVE OPERATION PERFORMANCE OF MICROGRID
Authors
응웬칸록
Keywords
controlstrategiesfordgstoimproveoperationperformanceofmicrogrid
Issue Date
2011
Publisher
인하대학교
Abstract
This dissertation presents a control strategy for distributed generators including controllable and uncontrollable sources to improve operation performance of micgrogrids. In order to achieve the control strategy for controllable DGs, the frequency and active power responses according to the droop characteristic have been investigated to show advantages and disadvantages of different microgrid configurations and different control modes. The analysis is based on three conditions of operations, i.e. grid-connected mode, islanded mode, and transition mode, and four possible configurations of the microgrid namely the FFC-series-, FFC-parallel-, UPC-series-, and UPC-parallel- configuration. According to the analysis, control strategy for controllable DGs is proposed to take the advantages and overcome the disadvantages of each configuration. Namely, the control strategy for controllable DGs is to operate the microgrid as constant load from the utility viewpoint, minimize the frequency change in the transition mode, and control the frequency unchanged during the islanded mode. Uncontrollable sources like PV and Wind turbine coupled with controllable sources like Fuelcell in a hybrid system can become controllable. The operation algorithm for hybrid sources, i.e. the PV-PEMFC hybrid source, based on the unit-power-control mode and feeder-flow-control mode is proposed to operate in the microgrid with a high efficiency, maximize the solar energy, and optimize the PEMFC operational efficiency. Overall control strategy for microgrid with presence of controllable DGs and the PV-PEMFC hybrid system is finally implemented in a multi-feeder microgrid in EMTDC/PSCAD. The simulation results show advantages and improvements of proposed method over conventional control method.
Description
Chapter I: Introduction 1 1.1 Motivations and Purposes 1 1.2 Highlights and Major Contributions 4 1.3 Dissertation Structure 6 Chapter II: Microgrid Concept and Control 9 2.1 Overview 9 2.2 Microgrid Management and Control 10 2.3 Microsource Controller 14 2.3.1 The Two Power Control Modes 18 2.3.2 Droop Control through Active and Reactive Power 20 Chapter III: Analysis of P and f Responses According to Microgrid Configurations 31 3.1 Overview 31 3.2 Active Power and Frequency Response in a Microgrid 33 3.2.1 Active Power and Frequency Response in Transition Mode 34 3.2.2 Active Power and Frequency Response in Grid Connected Mode 40 3.2.3 Active Power and Frequency Response in Islanded Mode 42 3.2.4 Comparison of the Different Microgrid Configurations 48 Chapter IV: Control Strategies for Controllable DGs in Microgrid 53 4.1 Overview 53 4.2 Control strategy for Microgrid in the Grid-connected Mode 54 4.2.1 Control Strategy for Single-Feeder Microgrid 54 4.2.2 Control Strategy for Multi-Feeder Microgrid 63 4.3 Control Strategy for Microgrid in the Islanded Mode 65 4.4 Simulation Studies and Results 67 4.4.1 Test System and Simulation Scenarios 67 4.4.2 Simulation Results in the Grid-Connected Mode 69 4.4.3 Simulation Results in the Transition Mode 73 Chapter V: Control Strategies for a Hybrid Source Connected to Microgrid 77 5.1 Overview 77 5.2 Hybrid System Description 78 5.2.1 Structure of Grid Connected Hybrid System 78 5.2.2 PV Array Model 79 5.2.3 PEMFC Model 81 5.2.4 Maximum Power Point Tracking Control 82 5.3 Control Algorithm of the Hybrid System 85 5.3.1 Control Strategy for the Hybrid System in the UPC mode 85 5.3.2 Overall Control Strategy for the Hybrid System 92 5.4 Simulation Studies and Results 97 5.4.1 Simulation Results in the Case without Hysteresis 97 5.4.2 Improving Operation Performance by Using Hysteresis 99 5.4.3 Discussion 100 Chapter VI: Case St
URI
http://dspace.inha.ac.kr/handle/10505/22599
Appears in Collections:
Medical School/College of Medicine (의학전문대학원/의과대학) > Medical Science (의학) > Theses(의학 석박사 학위논문)
Files in This Item:
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