ANALYSIS AND CONTROL OF MODES OF POWER SYSTEM FOR ENHANCING OPERATIONAL EFFECTIVENESS OF POWER MARKET

MINISTRY OF EDUCATION AND TRAINING THE UNIVERSITY OF DANANG TRAN PHUONG NAM ANALYSIS AND CONTROL OF MODES OF POWER SYSTEM FOR ENHANCING OPERATIONAL EFFECTIVENESS OF POWER MARKET Major: Power System & Network Code: 62.52.50.05 SUMMARY OF DOCTORAL DISSERTATION Danang - 2016 This dissertation has been finished at: The University of Danang The supervisors 1: Ass Prof Dinh Thanh Viet The supervisors 2: Prof La Van Ut Reviewers 1: Prof Tran Dinh Long Reviewers 2: Ass Prof Vo Ngoc Dieu Reviewers 3: Prof Nguyen Hong Anh The dissertation is protected before the council meeting marked doctoral dissertation at the University of Danang in December 26, 2015 08:30am Dissertation can be found at: - National library of Viet Nam, Hanoi - Learning & Information Resource Center, the University of Danang INRODUCTION Rationale Nowadays, the operation of power systems in the power market model has been researched and applied by many countries In Vietnam, starting on July 1st, 2012 competitive source power market has been operation Problem analysis and control of power system mode to enhance the operational efficiency of the power market, it has an important role and great significance In particular, assessement and control of congestion as well as voltage stability power system are not only safe operation of power system but also economic operation of power market, it should be considered study Aims of study - Study and analysis of the power system congestion in power market operation - Study and analysis of voltage stability of power system in power market operation - Study of FACTS devices for congestion control, voltage stability control and power market welfare - Design website model for congestion as well as voltage stability monitoring in spot market operation - Study of design congestion as well as voltage stability monitoring model in spot market operation Subjects and scope of study - Subjects: LUF factor, dV/dQ, LMP and social welfare; neural network; SVC and TCSC; information technology infrastructure of power market - Scope of study: congestion and voltage stability in power market operation of IEEE 39 bus and Vietnam power system in 2016 Methodology From document, experiment study and mathematical model CHAPTER 1: OVERVIEW OF POWER MARKET AND POWER SYSTEM OPERATION IN POWER MARKET MECHANISM 1.1 Deregulate electricity sector and towal competitive power market Electricity sector restructuring has been researched and applied by many countries Depending on the characteristics of the power system, political mode, the restructure purpose of each country is different so that electricity sector restructuring is different 1.2 Introduction to competitive power markets Power market models has been introduted as: competitive power generation market with a single buyer, competitive wholesale power market, competitive retail power market 1.3 Introduction to power market model in the world and Vietnam Power market models has been introduted as: Asia power market, Australia power market, United states of america power market, Europe power market, Vietnam power market Generation market 2005 2009 Testing Wholesale market 2014 Full 2016 Testing Retail market 2022 Full 2024 Testing Full Fig 1.5: The levels of development of the Vietnam power market 1.4 Power market operation 1.4.1 Day ahead market and spot market SMO GenCo/ DisCo ● Check quotations ● mobilization schedule of day ahead market ● Mobilization schedule of hour ahead market ● Dispatch Day ahead market (Day D-1) Spot market (Day D) ● Quotations of day D ● Announces the availability power level (only in case of problems) ● Operates generators following dispatch ● Calculate price market and payment Day D+1 Fig 1.7: Day ahead market and spot market 1.4.2 Bid, auction and mobilization schedue in power market The auction is arranged according to the capacity ranges from low to high price for supply curves and vice versa for demand curves Auction in the power market is operated by SMO, which is based on the quotations of the buyer and the seller 1.4.3 Optimal power flow in the power market The objective function is a minimum of social welfare in total: nG nD i 1 j 1 Min( CGi ( PGi )   BDj ( PDj )) (1.3) 1.4.4 Some economic criteria in the power market Locational marginal price - LMP at Busi is three components included in the marginal price at reference bus, marginal loss cost from reference bus to Busi and marginal congestion price from reference bus to Busi: LMPi  i  ref  lossi  congestioni ($ / h) Revenue of GenCo and payment or DisCo payment: (1.11) RGenCoi ( DisCoj )  LMPi  Pi (1.12) ($ / h) Profit of GenCo and DisCo is determined as: GenCoi  RGenCoi  CGenCoi ($ / h) (1.13) DisCoj  BDisCoj  RDisCoj ($ / h) (1.14) Hourly social welfare can be determined as: nG nD i 1 j 1  hSocial   GenCoi    DisCoj ($ / h) (1.15) Moreover, annual electricity losses can be determined as: A  Pmax  (MWh / year ) (1.16) Thus, cost for annual electricity losses can be determined as: Y  A  c ($ / year ) (1.17) 1.5 Analysis and control modes of power system in power market operation 1.5.1 Analysis and control congestion - Congestion analysis methods: Congestion analysis on line utilization factor - LUF, congestion analysis on locational marginal price - LMP - Methods of congestion control and management: using economics method such as locational marginal price - LMP, Financial Transmission Right - FTR; using techniques such as building new lines, upgrading and overload protection for the old line; adding compensation devices to increase power system control (fixed compensation and FACTS devices…) 1.5.2 Analysis and control voltage stability - Voltage stability analysis methods: Continuation power flow CPF, V-Q sensitivity - Voltage control methods: Excitation current adjusting of the generator, output voltage adjusting of transformer by voltage fixel divider or on load tap changer - OLTC, using compensation device for change voltage loss on the line as synchronous compensator, fixed capacitor, FACTS devices… 1.5.3 The impact of power system modes control on power market’s criterias Power system modes control will change power market’s criterias in formulas 1.11, 1.12 and 1.17 CHƯƠNG 2: ANALYSIS AND ASSESSMENT VOLTAGE STABILITY OF POWER SYSTEM IN POWER MARKET OPERATION 2.1 Background With analysis and control of power system’s modes in power market condition, analysis and assessement voltage stability through dV/dQ sensitivity will be implemented the lager number of calculation to implement system of equations Power system in power market condition is heavily influenced from the power market elements (bid, auction, mobilization schedule…) Need to find a new analysis and assessement voltage stability for power market 2.2 Voltage stability of power system Voltage stability related to the ability to capacity balance of the load buses, particularly reactive power balance 2.3 Analysis and assessement voltage stability of power system in spot market 2.3.1 The impact of quotations element on analysis and assessment of power system The objective function relating to quotations: ng ng i 1 i 1 Min (CGi ( PGi )) D1 Min (ai  bi PGi  ci PGi2 ) (2.4) The system of equations is determined from Newton -Raphson: J PV     J QV   V   P   J P  Q    J    Q (2.5) J R1 matrix is determined as: J R1  V Q (2.8) Diagonal elements of J R1 is V-Q sensitivity at buse 2.3.2 Artificial neural network for technical analysis and assessement Neural network Input p w n  f a b Fig 2.5: Neural network with one input Types of error of neural network assessement between target value ti and assessement value can be determined as: Actual error: ei  ti  (2.10) Absolute error: ei  ti  (2.11) MAE  Mean Absolute Error: n  ei n i 1 Mean Absolute Percentage Error: MAPE  (2.12) n ei  100 (2.13) n i 1 ti n (2.14)  (ei )2 n i 1 Where: ti is target value, is assessement value, n is the MSE  Mean Squared Error: number of text sample 2.3.3 Design neural network for application of analysis and assessement voltage stability of power system in spot market - For basic neural network structure: Input Hidden Output PgT SCADA system T Qg (dV/dQ)T Pl T QlT VT Fig 2.6: MLP neural network model with basic structure - For neural network structure of proposal dissertation: Input Hidden Output PgT SCADA system QgT Pl T QlT Biding system T V (dV/dQ)T CgT Fig 2.7: MLP neural network model with structure of proposal dissertation (VSA-PM) 2.3.4 Algorithm flowchart of neural network training in voltage stability assessement of power system in spot market Algorithm flowchart is impletemented as: create neural network; create learning text sample; create weight, bias, the number of iterations; training by Levenberg - Marquardt algorithm; checking stop condition; saving neural network structure with new weight and bias; text neural network 2.3.5 Application of neural network in analysis and assessement voltage stability of IEEE 39 bus power system in spot market - Analysis neural network training perpormance: Fig 2.11: Error MSE: (a) basic structure, (b) proposal structure 11 Training Best Epochs (b) Fig 2.23: Error MSE: (a) basic structure, (b) proposal structure - Text and analysis neural network with examined data: (a) Distribution of absolute error, MAE=4.13e-07 Absolute error MAE (b) Distribution of absolute percentage error, MAPE=0.5887% Absolute percentage error MAPE Fig 2.24: Distribution of absolute error, absolute percentage error with basic structure (a) Distribution of absolute error, MAE=2.89e-07 Absolute error MAE (b) Distribution of absolute percentage error, MAPE=0.4370% Absolute percentage error MAPE Fig 2.25: Distribution of absolute error, absolute percentage error with proposal structure 12 - Text and analysis neural network with mutations data: Sample value (PowerWorld) ANN value (Matlab) Bus Fig 2.28: Assessement dV/dQ, error MAE and error MAPE of basic structure with disconnected branch 500KV Tan Dinh - Song May Sample value (PowerWorld) ANN value (Matlab) Bus Fig 2.29: Assessement dV/dQ, error MAE and error MAPE of proposal structure with disconnected branch 500KV Tan Dinh - Song May 13 Therefore, proposal neural network structure shows assessement performance through error of MSE, MAE, MAPE are better than the basic neural network structrure for Southern Vietnam bus power system in 2016 CHAPTER 3: STUDY AND APPLICATION OF FACTS DEVICE CONTROL OF MODES OF POWER SYSTEM FOR ENHANCING EFFECTIVENESS OF POWER MARKET 3.1 Background With premium features and benefits of FACTS devices, research and installation of FACTS will be expected the effective operation of the power system and power market 3.2 Overview of FACTS device With specifications, SVC, STATCOM, UPFC devices can be utilized to enhance voltage stability as well as TCSC, UPFC devices can be utilized to control power flow With economic criteria, cost of SVC and TCSC following KVAr are cheaper than other FACTS devices Dissertation choose SVC and TCSC to calculate and connect operational power system in conditional power market 3.3 Application of choice placement of FACTS device for modes control of power system in power market operation 3.3.1 The impact of FACTS device to modes control of power system to power market’s criterias Application of FACTS device will change power flow in power system, so criterias of GenCos, DisCos and market will change as formulas from 1.13 to 1.17 14 3.3.2 Methodology of choice placement of FACTS device into power system in power market operation With methodology of choice placement of TCSC as well as SVC into power system in power market operation, it will be analyzed the technology first, and then it will analyze the economic after 3.3.3 Assessment FACTS device efficiency to enhance benefit of electricity losses Dissertation proposes choice of placement of FACTS device following criteria for benefit of electricity losses fall: (3.20) BLFACTS  D(A )  c ($) Criteria for benefit of electricity losses fall with scenarios: n scenarioi BLFACTS   BLFACTS ($) _ scenarioi  t (3.21) i 1 3.4 Analysis and choice of placement of FACTS device in IEEE 39 bus power market 3.4.1 Analysis and choice of placement of SVC SVC is located alternate weak buses of voltage stability, and P-V is analyzed next, effectiveness achieves positive effects The slope of the P-V curves are reduce, voltage Vmin of curves are improved with the connection cases of SVC Tab 3.3: Change criterias of P-V cuver with connection cases of SVC Without SVC Bus 26 Bus 27 Bus 28 Bus 29 Ptotal-max (pu) 4,725 4,725 4,725 4,725 4,725 Vmin (pu) 1,015 1,016 1,016 1,028 1,053 With two SVC effective cases, case of SVC connection at bus SVC 29 shows the highest economic efficiency through BL value 15 Control value Average value Fig 3.14: Annual BLSVC criteria in connection cases of SVC with control V=1,02pu and V=1,03pu 3.4.2 Analysis and choice of placement of TCSC With two TCSC effective cases, case of TCSC connection at TCSC branch 4-14 shows the highest economic efficiency through BL value Control value Average value TCSC Fig 3.19: Annual BL criteria in connection cases of TCSC with control XTCSC= 0,5XL and XTCSC= 0,7XL 3.5 Analysis and choice of placement of FACTS device in Vietnam power market in 2016 3.5.1 Analysis and choice of placement of SVC 16 With three SVC effective cases, case of SVC connection at bus Tan Dinh shows the highest economic efficiency through BLSVC value Control value Average value Fig 3.26: Annual BLSVC criteria in connection cases of SVC with control V=1,02pu and V=1,03pu 3.5.2 Analysis and choice of placement of TCSC With two TCSC effective cases, case of TCSC connection at branch Di Linh - Tan Dinh shows the highest economic efficiency through B/C value Control value Average value TCSC Fig 3.27: Annual BL criteria in connection cases of TCSC with control XTCSC= 0,7XL and XTCSC= 0,75XL 17 CHAPTER 4: STUDY AND DESIGN OF MONITORING AND CONTROL MODES OF POWER SYSTEM IN POWER MARKET OPERATION 4.1 Background Nowadays, the information technology infrastructure of electrical sector in many countries around the world are upgrading development However, when the power market operation, the completion of hardware and software of the information technology infrastructure is an important issue of power market 4.2 Overview of SCADA/EMS system SCADA/EMS is supervisory control and data acquisition/Energy Management System This system is the optimal control center solution to enable a secure and efficient operation of the electric power system 4.3 Introduction of SCADA/EMS system of Vietnam power system According to overall assessment, SCADA/EMS should be further upgraded to meet the high operation requirements as well as mechanism power system 4.4 Connection of SCADA/EMS with operational system of power market In mechanism power market, SCADA/EMS system is connected directly to power market operational system SCADA/EMS system focus to collect, monitor and control power system, operational system of power market focus to operate transaction of the members participating in the power market 18 4.5 Website model design for monitoring of voltage stability and congestion in spot market (WEB-CVM-PM) Fig 4.7: Page of congestion collection data Fig 4.8: Page of congestion assessement 19 Fig 4.9: Page of voltage stability collection data Fig 4.10: Page of voltage stability assessement ASP.NET language is used to design web The web structure includes one the homepage Index and six main page for descriptions, user manual, statistical data collection and congestion assessement, statistical data collection and voltage stability assessement 20 4.6 Proposal of model for monitoring and control of congestion of power system in spot market The model combine between the voltage stability assessement method with LUF factor for monitoring, assessement and control congestion in spot market is proposed as Fig.4.11 In this proposed model, the parameters signal of transmission capacity on the branchs are sent from RTU and SCADA through SCADA/EMS system of electrical power system, the parameters of capacity limits on the branch are sent from data center as proposed in chapter Website implement the publication and monitoring of congestion In addition, TCSC with suitable location has been selected and adjustment (mentioned in Chapter 3) will be used to control congestion of power system to enhance social welfare Power system Signal from RTU/IED SCADA/EMS system MVAij System data MVAijmax Assessement LUF on-line WEB-CVM-PM monitoring No congestion Congestion TCSC Congestion control Fig 4.11: Model of monitoring and control of congestion of power system in spot market 21 4.7 Proposal of model for monitoring and control of voltage stability of power system in spot market In this proposed model, the parameters signal of buses are sent from RTU and SCADA through SCADA/EMS system of electrical power system, bids of spot market hour ahead market are sent GenCos through bid system of power market MLP neural network is applicated to design voltage stability assessement as proposed in chapter Website implement the publication and monitoring of voltage stability In addition, SVC with suitable location has been selected and adjustment (discussed in Chapter 3) will be used to control voltage stability of power system to enhance social welfare Power system Quotation from GenCos Calculate dV/dQ off-line System data Training MLP off-line MLP data Auction system Signal from RTU/IED SCADA/EMS system VSA-PM asesses dV/dQ on-line WEB-CVM-PM monitoring Stability No stability Off-line training Monitoring and control on-line SVC voltage control Fig 4.12: Model of monitoring and control of voltage stability of power system in spot market 22 CONCLUSION AND FUTURE WORK Conclusion - The dissertation has proposed a new method (VSA-PM) to analysis and assess voltage stability of power system in power market operation The model combines between the MLP neural network with dV/dQ sensitivity MLP neural network structure is added a vecto C gT that are related to information from GenCos’s quotations - The dissertation has applicated VSA-PM to analysis and assess error of MSE, MAE and MAPE in IEEE 39 bus and southern Vietnam in 2016 The new method VSA-PM has achieved positive results in voltage stability in spot market This new method has been more effective than the structure of the previous study (reduction of error MSE, MAE, MAPE) - The dissertation has proposed method of choice of placement of FACTS device (SVC, TCSC) for power system in power market operation with techno-economic criterias Technical criteria is boundary conditions, economic criteria is prerequisite Technical criteria is LUF factor for TCSC and dV/dPtotal (curve slope P-V) for SVC; the considered economic criteria is benefits in electricity losses fall of FACTS device - With new proposal method, dissertation applied to calculate and analyze in IEEE 39 bus power system and southern Vietnam power system in 2016 In the case of IEEE 39 power system, the most efficient location to install SVC is the connection bus 29, the location for TCSC is at branch 4-14 In the case of south Vietnam power system in 2016, the most efficient location to install SVC is at bus Tan FACTS Dinh, TCSC at branch Di Linh - Tan Dinh Moreover, via the BL 23 criteria, the dissertation has compared the efficiency between SVC and TCSC, and the results have shown that TCSC brings about more economic values than SVC - The dissertation has proposed a website model for monitoring of voltage stability and congestion in spot market (WEB-CVM-PM) - With new proposal website, dissertation has applied a monitoring and control of congestion as well as voltage stability in spot market This model combines between proposal method of congestion and voltage stability, WEB-CVM-PM and SVC/TCSC Future work - In technology development of integrated circuit technology, it should research to design a microchip controller for voltage stability assessement of power system in power market through VSA-PM method - In the ultra high voltage power system with great length as Vietnam power system, Northern’s operational problems had little effect on the South and vice versa Maybe study to find the optimal placement of FACTS devices for each region Therefore, the proposed algorithm and methodology of mixed FACTS devices (the same type or different type) through technology and economic criteria will be studied for the future 24 THE AUTHOR’S PAPERS HAVE BEEN PUBLISHED [1] Tran Phuong Nam, Dinh Thanh Viet (2010), “A Study of the Sparse Matrix Solution Techniques Applied in Computation and Analysis of Power Systems”, Journal of Science and Technology, University of Danang, vol 6(41), pp 37-43, ISSN 1859-1531 [2] Dinh Thanh Viet, Tran Phuong Nam (2012), “Application of SVC to Enhance the Operational Efficiency of Power Market”, Journal of Science and Technology, University of Danang, vol 12(61), pp 137-141, ISSN 1859-1531 [3] Tran Phuong Nam (2012), Study, Simulation and Analysis of Power Market, Research & Development - Grassroots level, No 151/HĐ-CĐCNH/QLKH, 19/12/2012 [4] Tran Phuong Nam, Dinh Thanh Viet, La Van Ut and Tran Tan Vinh (2014), “Website Design for Voltage Stability Monitoring and Assessment in Power Market”, Journal of Science and Technology, University of Danang, vol 12(85), pp 64-68, ISSN 1859-1531 / in Proc Conf CITA 2014, Danang, Vietnam, pp 24-28 [5] Tran Phuong Nam, Dinh Thanh Viet (2012), “Development of Distributed Generation in Power Market”, Journal of Science and Technology, University of Danang, vol 12(61), pp 137141, ISSN 1859-1531 / in Proc Conf UK-VN CECE 2012, Danang, Vietnam [6] Tran Phuong Nam, Dinh Thanh Viet, and La Van Ut (2015), “Optimal placement of TCSC in Power Market”, International 25 Journal of Electrical Energy, vol 3, no 1, pp 43-47, ISSN 2301-3656, Indexed by: EI / in Proc Conf ICPES 2014, Singapore [7] Dinh Thanh Viet, Tran Phuong Nam, and La Van Ut (2013, “Analysis of Profit of Generation Company in Power Market”, Journal of Optoelectronic Information-Power Technologies, vol 26, no 2, pp 75-78, ISSN 2311-2662 [8] Tran Phuong Nam, Dinh Thanh Viet, and La Van Ut (2012), “Application of Neural Network in Voltage Stability Assessment in Real-time Power Market”, in Proc IEEE Conf IPEC 2012, Ho Chi Minh, Vietnam, pp 196-200 [9] Tran Phuong Nam, Dinh Thanh Viet, and La Van Ut (2013), “Application of SVC for Voltage Regulation in Real-time Power Market”, in Proc IEEE Conf ICIEA 2013, Melbourne, Australia, pp 538-543 [10] Le Hong Lam, Tran Phuong Nam, and Ming-Tse Kuo (2014), “Optimal Location of Power Plant in Power Market”, in Proc IEEE Conf IGBSG 2014, Taipei, Taiwan, pp 1-4 [11] Tran Phuong Nam, Le Hong Lam, Ming-Tse Kuo, and Dinh Thanh Viet (2014), “Analysis Profit of Generation Company in Power Market by Bidding Strategy”, in Proc IEEE Conf IGBSG 2014, Taipei, Taiwan, pp 1-4 [12] Tran Phuong Nam, Dinh Thanh Viet, and La Van Ut (2014), “Optimal Placement of SVC in Power Market”, in Proc IEEE Conf ICIEA 2014, Hangzhou, China, pp 1713-1718