Improving Reliability and Economic Performance of Microgrids

Transcription

1 Improving Reliability and Economic Performance of Microgrids - A short course jointly organized by School of Electrical and Electronic Engineering, NTU and IEEE Singapore Section Introduction In recent years, the renewable power generation has been seen as an effective way to resolve the global energy crisis and reduce the carbon footprint. However, the intermittent characteristics of renewable energy sources such as wind and solar energy systems give rise to great challenges on coordination and balancing issues between supply and demand. Microgrids as a platform to incorporate renewable and alternative energy resources and advanced energy storage systems can provide intelligence for monitoring and control of distribution systems to enhance their availability, reliability and efficiency. With the continuous and advanced development of the microgrid technologies, the basic theory and energy cooperation management technologies of the microgrids have been developed and improved. The researchers in both the academic and industrial sectors have been working hard on promoting the practical applications and commercialization of the microgrids. They still face many challenges such as improving the reliability, economic performance, and power quality issues. Since 2014, our research team has been working on the Economic Development Board (EDB) funded project entitled Improving Reliability and Economic Performance of Microgrids. In this project, a novel microgrid configuration including the adaptive demand response management (DRM), advanced solid state transformer (SST) based hybrid energy storage system (HESS) and unified power quality conditioner (UPQC) is proposed as shown in Figure 1. Forecasting of solar and wind Grid Wind and solar irradiance data Power Quality Improvement with UPQC UPQC Vdc Wind Solar PV Micro Turbine Electricity pricing Demand Response Management Energy Management System for Economic Dispatch Charge and Discharge commands to HESS Hybrid Energy Storage System Energy Management Market Operations System HFT SST AC Loads Maximum Demand Control with Contracted Capacity Optimization Local Control Agents Generation Scheduling HESS Power Quality and Reliability Battery Fuel Cell Electricity Bill Reduction Local Protection Elements Communication and control network Electrical Network Figure 1. Configuration of the proposed microgrid including the UPQC, HESS and adaptive DRM 1

2 By using the adaptive demand response management (DRM), SST based HESS and UPQC, the microgrid is expected to mitigate the intermittent nature of renewable energy sources; improve the power quality of the supply; lower the schedule cost; as well as balance the supply and demand. This course will reveal the latest research achievements of this EDB funded project. The following aspects of the project will be taught in the course: (1) The functionalities of adaptive DRM operating in microgrids is shown in Figure 2. Compared to DRM applied in upstream grids, DRM applied in microgrids in an interconnected mode will further improve the market efficiency. With the support of DRM applied in microgrids, even the small customers are able to respond to real-time market prices. The impact of DRM can thus be extended to a larger variety of customers. With a higher participation rate of the customers in DRM, peak demand could be further lowered by incentivized consumers who respond to a higher real-time price via automated intelligent energy management devices. Therefore, the total generation cost can be reduced and generation efficiency will be improved. From an economic benefit viewpoint, an effective DRM system is able to optimize the total profits of microgrids by taking into account the unique features of the distributed generation resources in microgrids. Figure 2. Functionalities of DRM operating in microgrids (2) The configuration of HESS connected to a microgrid using SST is shown in Figure 3. The HESS consists of batteries, supercapacitors and power converter systems via SSTs. By combining the advantages of high energy density capability of batteries, and high power density capability of supercapacitors, HESS possesses a superb capability for managing highly fluctuating power demands. Further, HESS is used to improve the reliability, power quality, dynamic performance, and overall microgrid schedule/operating cost. Through optimal 2

3 power scheduling solutions of HESS, the HESS will be more cost-effective than the singletype storage system. Since the SST is adopted in the HESS as the grid-connected interface, the proposed technique enjoys a much reduced weight and size as compared to those conventional power conversion approaches utilizing the power electronics converters and regular power transformers. Besides the basic functions of charging/discharging the batteries/supercapacitors, the SST based HESS possesses the advantages of voltage/frequency adaption and reactive power compensation. Battery SST LA LB LC Microgrid HFT AC Supercapacitor SST LA LB LC HFT AC Figure 3. SST based HESS (3) UPQC is connected between the main grid and microgrid as shown in Figure 4. The power transfer between main grid and the microgrid is bidirectional depending upon the power generation in the microgrid. UPQC is able to mitigate both voltage and current power quality problems. It protects the sensitive microgrid loads and power electronic based renewable power generation systems from the power quality problems in the grid such as voltage harmonics, unbalanced voltages, voltage sags and voltage swells. In addition, this UPQC makes the main grid free from the current power quality problems created by the nonlinear loads in the microgrid by means of supplying the reactive power and suppressing the harmonics. Hence, this UPQC improves the reliability of the microgrid. Figure 4. UPQC interconnected between main grid and microgrid 3

4 (4) Short course participants will be introduced to two main development and testing concepts i.e. rapid control prototyping (RCP) and hardware in the loop (HIL). They will learn how to adopt the appropriate concepts depending on the user requirement. An illustration of the development and testing concepts is shown in Figure 5. Fgiure 5. Development and testing via rapid control prototyping and hardware-in-the-loop Hardware and Software Demonstration Demonstration of the abovementioned technologies based on the self-developed DRM software and the self-built experimental prototypes of the SST based HESS, UPQC and PHIL in the laboratory. DRM: Maximum Demand Control (M) as a part of DRM reduces the electricity bill of a microgrid or building consumer/owner; increases load factor; and smoothens the system load profile. M includes three applications namely Short-Term Maximum Demand Control (STM), Real-Time Maximum Demand Control (RTM) and Contracted Capacity Optimization (CCO). In the hardware cum software demonstration, the following features of M will be presented: (a) Demonstration of CCO software and its modules; (b) Demonstration of STM software and its modules; (c) Demonstration of M software and its module; (d) Explanation of the real-time test system and load profile; (e) Explanation of the controllable loads which are used in the test; (f) Running the system to demonstrate the effect of system parameters and variables; and (g) Demonstration of its outputs: graphs and numerical results. SST and HESS: We will perform the following hardware demonstrations: (a) Introduction of SST and HESS configuration and principle of operation; (b) Demonstration of charging/discharging of the battery/supercapacitor via SST and HESS; 4

5 (c) Demonstration of parallel operation of SSTs including online switching between single SST and two SSTs to validate the extensibility, redundancy and re-configurability benefits; (d) Demonstration of energy management of the battery/supercapacitor; (e) Demonstration of state of charge (SoC) regulation of the battery, i.e. operating within the limits of SoC, through a coordinated control with the supercapacitor; (f) Demonstration of bus voltage regulation of HESS; (g) Demonstration of power sharing between the battery and supercapacitor; (h) Demonstration of control of power sharing between the grid and HESS w.r.t. load demand. UPQC: Demonstration of the UPQC is done for verifying its voltage and current mitigation capabilities. Voltage compensation capability is demonstrated by regulating the microgrid voltage even with the sag and swell conditions in the main grid. The voltage sag and swell conditions in the main grid are created by connecting auto transformer to the grid. The current power quality mitigation capability is demonstrated by maintaining the balanced and sinusoidal currents from the grid even with the nonlinear load currents in the microgrid. The nonlinear loads are emulated in the microgrid using the Chroma programmable load. PHIL: Power hardware in the loop (PHIL) concept will be introduced which is a natural extension of HIL. Participants will have an opportunity to view a real time demonstration of PHIL experiments on the microgrid testbed at the Clean Energy Research Lab (S2-B7c-05) in EEE, NTU. The PHIL experiment is performed using the state-of-art real time digital simulator from OPAL-RT and a four quadrant power amplifier from Triphase. An overview of the PHIL architecture is shown in Figure 6. Figure 6. Proposed testing and architecture of power hardware in the loop (PHIL) concepts We will perform the following hardware demonstrations (i) Introduction of PHIL between the real-time simulator, OPAL-RT, and HESS; 5

6 (ii) Demonstration of controlling the charging/discharging phenomenon of the battery to regulate the grid voltage and frequency by configuring PHIL using OPAL-RT and HESS. Course Objectives In this course, four presentations related to the adaptive DRM, the UPQC with DG sources and the advanced SST based HESS will be conducted. The basic concept, development and principle of these technologies will be introduced in detail. In the demonstration section, the function and effectiveness of the adaptive DRM will be validated using the completed DRM software based on the microgrid in our lab. The hardware configuration, design and implementation of the self-developed experimental laboratory prototypes of the SST based HESS and UPQC will be introduced. The various operating modes and pre-set functions of them will be demonstrated to validate the feasibility and practicability of these proposed technologies. It is expected that through this course, the participants are able to understand the principle of operation, current R&D trend and the challenges of the technologies towards the improvement of the economic performance and reliability and power quality of the microgrid. This course is also a good opportunity to showcase and share with the participants our latest research achievements in terms of improvement in the reliability and economic performance and power quality of the microgrid. Furthermore, we would share with the participants the design rules and implementation methodology of the proposed DRM, SST based HESS and UPQC to promote the commercialization of these technologies. 6

7 Course Outline Time Activities 8:30-9:00 Registration 9:00-10:00 Lectures delivered by Prof Hoay Beng Gooi Topic: Overview of Microgrid Management and Latest Development Trend 1. Overview of Microgrid Management System 2. Demand Response Management 3. Some Aspects of Latest Development Trend 10:00-10:30 Tea break 10:30-11:30 Lectures delivered by Prof Fengjiang Wu and Dr Sathish Kumar Kollimalla Topic: Hybrid Energy Storage System (HESS) and Solid State Transformer (SST) Advancement in Energy Management System for Smart Grid 1. Overview of HESS and SST 2. Configuration and control algorithms of HESS 3. Concept, configuration and potential application of SST 4. Control algorithm, design and implementation of SST for HESS 11:30-12:30 Lectures delivered by Prof Yi Tang Topic: Unified Power Quality Conditioner (UPQC) 1. Introduction to power quality. 2. Solutions for power quality problems. 3. Working and control principles of UPQC. 12:30-13:30 Lunch 13:30-14:30 Lectures delivered by Dr Foo Eddy Topic: Power Hardware-in-the-Loop (PHIL) 1. Overview of Real Time Digital Simulator 2. Rapid Control Prototyping, Hardware in the loop and PHIL concepts 3. PHIL applications 4. Example on NTU microgrid PHIL scenario 14:30-16:00 Hardware and Software Demonstration: DRM, SST based HESS, UPQC and PHIL in the Clean Energy Research Laboratory (S2-B7c-05). 16:00-16:30 Tea Break 16:30-18:00 Hardware and Software Demonstration: DRM, SST based HESS, UPQC and PHIL in the Clean Energy Research Laboratory (S2-B7c-05). The details of the finalized course schedule will be available from the Short Course sub-menu at a couple weeks before the scheduled course date. 7

8 Instructors H. B. GOOI received his Ph.D. degree from Ohio State University in From 1983 to 1985 he was an Assistant Professor in the EE Department at Lafayette College. From 1985 to 1991 he was a Senior Engineer with Empros (now Siemens), USA where he was responsible for the design and testing of energy management system (EMS) projects. In 1991, he joined School of EEE, NTU as a Senior Lecturer and has been an Associate Professor since He is a registered professional engineer in USA and Singapore. He taught EMS courses for dispatchers at Power System Control Centre in Singapore, Indonesia and Malaysia. He was Deputy Head of Power Engineering Division during He serves as an Editor of IEEE Transactions on Power Systems. He attracted more than S$10m research grants and serves as PI of EIRP04 and EIRP12 Project. His current research interests include microgrid energy management systems, energy storage, renewable energy sources, electricity market and spinning reserve. Fengjiang Wu received the B.S., M.S. and Ph.D. degrees in electrical engineering from Harbin Institute of Technology (HIT), Harbin, China, in 2002, 2004 and 2007, respectively. Since 2007, he has been with the Department of Electrical Engineering, HIT, where he is currently an Associate Professor. Since 2016, he has been with the School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, as a Senior Research Fellow. His research interests include the area of renewable energy generation, energy storage system, microgrid, multilevel inverter technology and electric machines drive. He has published more than 40 international journal and conference papers. He has filed more than 20 patents and some of them are pending. Sathish Kumar Kollimalla received the Bachelor s degree from the Viswanadha Institute of Technology and Management College of Engineering, Visakhapatnam, India, in 2003, and the Master degree in engineering from Andhra University, Visakhapatnam, in He received the Ph.D. degree from Indian Institute of Technology Madras, Chennai, India in He has worked as senior research fellow in Central Power Research Institute, Bangalore, India during 2008 to Currently he is holding a position of Post-Doctoral Research Fellow in Nanyang Technological University, Singapore. His research interests include power electronics applications in power systems, microgrid, renewable energy systems, hybrid energy storage system and power quality. 8

9 Yi Tang received the B.Eng. degree in electrical engineering from Wuhan University, Wuhan, China, in 2007 and the M.Sc. and Ph.D. degrees from the School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, in 2008 and 2011, respectively. From 2011 to 2013, he was a Senior Application Engineer with Infineon Technologies Asia Pacific, Singapore. From 2013 to 2015, he was a Postdoctoral Research Fellow with Aalborg University, Aalborg, Denmark. Since March 2015, he has been with Nanyang Technological University, Singapore as an Assistant Professor. He is the Cluster Director of the advanced power electronics research program at the Energy Research Institute. Dr. Tang serves as an Associate Editor for the IEEE Journal of Emerging and Selected Topics in Power Electronics. He received the Infineon Top Inventor Award in Y. S. Foo. Eddy received his B.Eng. degree in Electrical and Electronic Engineering from Nanyang Technological University, Singapore, in Subsequently, he received his Ph.D. degree in Electrical and Electronic Engineering from Nanyang Technological University, Singapore, in Between 2014 and 2016, he worked as a research engineer under the Cambridge Centre for Advanced Research in Education in Singapore (CARES) project which is part of the CREATE program. Between 2012 and 2014, he served as a Teaching Assistant for NTU EEE and REP. He was awarded the NTU EEE outstanding teaching award in At present, he is a lecturer in the School of Electrical and Electronic Engineering at Nanyang Technological University, Singapore. His research interests are multi-agent systems, microgrid energy management systems, electricity markets, power hardware in the loop and renewable energy resources. 9

10 Demonstrators N. K. Swami Naidu received the B. Tech. degree in electrical and electronics engineering from Jawaharlal Nehru Technological University (JNTU), Hyderabad, India, in 2007; the M.Tech. degree in power electronics and drives from the National Institute of Technology, Kurukshetra, India, in 2009; and the Ph.D. degree from the Electrical Engineering Department, Indian Institute of Technology Delhi, New Delhi, India, in He is currently working as a Research Fellow with Nanyang Technological University, Singapore. His research interests include power electronics, wind energy conversion systems, power quality, and microgrid-based power systems. Ali Khorasani Ferdavani received the B.Sc. and M.Sc. degrees from Ferdowsi University of Mashhad, Iran, in 1995 and 1998, respectively, and Ph.D. degree from the Universiti Teknologi Malaysia (UTM), Malaysia, in Electrical Engineering in He is currently a Research Fellow at Nanyang Technological University since Jan His previous job was at UTM under the Post-Doctoral Fellowship Scheme for a research project from Mar 2013 to Dec He was also a project manager in some consultant electrical distribution system projects such as preparation of comprehensive plans since Furthermore, he was a lecturer at Isfahan University of Technology from 2005 to His research interests include power system analysis and optimization, micro grid, smart grids, Internet of Things, reliability, and power quality. For the brief CV of Dr. Fengjiang Wu, Dr. Sathish Kumar Kollimalla and Dr Y. S. Foo. Eddy, please refer to the Instructor page. 10

11 Who Should Attend? This course is useful to engineers and managers working in clean energy, renewable energy, converter design and operation of smart grids, microgrids and intelligent energy systems. It is beneficial to anyone who wishes to know more about their development in Singapore. The course will be structured towards experience sharing and knowledge transfer. Course Information Date: July 27, 2017 (Thursday) Time: 8:30 to 18:00 Lecture Venue: Executive Seminar Room (S2.2-B2-53), Block S2.2, Level B2, Room 53, School of Electrical & Electronic Engineering (EEE), NTU Demo Venue: CPD Programme: Fee (net amount): Laboratory for Clean Energy Research (S2-B7c-05), School of EEE, NTU This course is qualified for 7 PDUs by Professional Engineers Board (PEB), Singapore. URL: S$600 or on site S$700 (subject to space availability) S$550 for early bird registration by July 10, 2017 or $500 for group registration (3 or more from the same organization registered at the same time by July 10, 2017) Fees include refreshments, lunch and course notes. Payment is to be made payable to IEEE Singapore Section via a Singapore cheque or bank draft in Singapore dollars. Overseas participants are asked to contact Mrs Jasmine Leong for details of TT transfer at: IEEE Singapore Section Secretariat Blk 121 Paya Lebar Way # Singapore Tel: (65) sec.singapore@ieee.org Accommodation is available at Nanyang Executive Center on a first-come, first-served basis. Details are available at The proposed course contents may be modified where practical and the course is subjected to a minimum participation before commencement. 11

12 Participant s Details Name: *(Mr/Ms/Mrs/Dr) Designation: Contact no: PEng: Yes/No Name: Designation: Contact no: PEng: Yes/No Name: Designation: Contact no: PEng: Yes/No Organization s Details Company Name: Company Address: Postal Code: Contact Person s Name: *(Mr/Ms/Mrs/Dr) Designation: Contact no: Fax: Please complete the form, scan and to the IEEE Singapore Section Secretariat before sending the original together with the cheque/bank draft to Mrs Jasmine Leong at: IEEE Singapore Section Secretariat Blk 121 Paya Lebar Way # Singapore Tel: (65) sec.singapore@ieee.org Payment by cheque/bank draft is to be made payable to IEEE Singapore Section in Singapore dollars. 12