Generation maintenance scheduling in competitive electricity markets based on game theory

학위논문 (석사)-- 서울대학교 대학원 : 전기. 컴퓨터공학부, 2011.2. 박종근.Maste

발전기 고장과 순부하 예측오차에 의한 증감발용량 부족위험의 평가방법

학위논문 (박사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2016. 2. 박종근.Increasing variable generation (such as wind power and photovoltaics) in power systems has required the system operators to secure more ramping capability (RC) to satisfy variations in net load. The more RC that is secured, the better the system is able to deal with the variations in net load. However, uncertainties inherent in generation resources (i.e., failure) as well as in net load forecasts make it harder to secure the RC. These uncertainties may trigger RC shortage, which can result in a reliability crisis. When considering the impact of the uncertainties, there exists no clear RC requirement. To determine how much RC is sufficient, the trade-off relationship between the risk of RC shortage and the operating costs of providing RC should be first taken into account. However, unlike the operating cost, the risk of RC shortage is not easily quantifiable. Although critical uncertainties such as failure of generators and NLFE have been mentioned as the cause of the risk of RC shortage, their causal relationship has not been explicitly addressed in previous researches on the risk of RC shortage. This dissertation proposes a risk assessment method for ramping capability (RC) shortage. Two major uncertainties in power systems are considered: generator failure and net load forecast error (NLFE). The failure probability of generators is calculated using a Markov-chain-based capacity state model, where two types of generator were considered depending on its initial state: one is a two-state model for generators that are initially committed, and another is a four-state model for generators that are not initially committed. The failure probability is calculated based on a simple matrix multiplication technique. Meanwhile, the NLFE is modeled as a normal distribution, which is represented using a seven-step approximation. The risk of RC shortage is evaluated using an index termed RC shortage expectation (RSE), which is defined as the sum of the probabilities that the RC requirement will be not satisfied by the system. Numerical examples were then presented to describe the RSE calculation procedure with and without NLFE and the generation schedules. A case study was carried out using a modified IEEE-RTS-96 to show the applicability of the method. The sensitivity analysis was also performed to find the relationship between the RSE and influencing parameters. The failure rate of the generators, the spinning reserve requirement, the installed capacity of wind farms were chosen as the parameters to represent the uncertainty, the operating scheme of the system operator, and the variability due to wind power, respectively. The reliance of the RSE on these parameters can enable the system operator to obtain useful information. If this method is combined with a well-developed cost estimation for generation schedules, then it is expected to be particularly useful for the system operator to determine the adequate RC level for a given power system.CHAPTER 1. INTRODUCTION 1 1.1 MOTIVATION FOR THE STUDY 1 1.2 LITERATURE SURVEY 3 1.3 OBJECTIVES OF THE DISSERTATION 5 1.4 ORGANIZATION OF THE DISSERTATION 6 CHAPTER 2. RISK OF RAMPING CAPABILITY SHORTAGE 7 2.1 RAMPING CAPABILITY 7 2.2 RISK OF RAMPING CAPABILITY SHORTAGE 9 CHAPTER 3. UNCERTAINTY MODEL 11 3.1 GENERATOR FAILURE 11 3.1.1 CAPACITY STATE MODELS 11 3.1.2 FAILURE PROBABILITY 12 3.2 NET LOAD FORECAST ERROR 14 CHAPTER 4. RISK ASSESSMENT OF RAMPING CAPABILITY SHORTAGE 15 4.1 WORST-CASE SCENARIO 15 4.2 RAMPING CAPABILITY SHORTAGE EXPECTATION (RSE) 17 CHAPTER 5. NUMERICAL EXAMPLES 18 5.1 RSE CALCULATION FOR E1 20 5.2 RSE CALCULATION FOR E2 22 5.3 RSE CALCULATION FOR E3 24 5.4 RESULT COMPARISON 26 CHAPTER 6. CASE STUDY 27 6.1 BASE CASE 27 6.2 RESULT OF BASE CASE 29 6.3 SENSITIVITY ANALYSIS 31 6.3.1 FAILURE RATE OF GENERATORS 32 6.3.2 RESERVE REQUIREMENT 41 6.3.3 INSTALLED CAPACITY OF WIND POWER 42 CHAPTER 7. CONCLUSION AND FUTURE WORK 43 BIBLIOGRAPHY 44 APPENDIX 49 A. MARKOV-CHAIN-BASED CAPACITY STATE MODELS OF GENERATORS 49 A.1 TRANSITION RATE 49 A.2 MARKOV CHAIN 50 A.3 STOCHASTIC TRANSITION MATRIX 51 A.4 MARKOV-CHAIN-BASED CAPACITY STATE MODELS OF GENERATORS 53 B. ESTIMATION OF WIND POWER GENERATION 54 C. CAPACITY CREDIT OF VARIABLE GENERATION 57 C.1 EFFECTIVE LOAD CARRYING CAPABILITY (ELCC) 57 D. A MODIFIED IEEE-RTS-96 59 D.1 BRIEF HISTORY OF IEEE-RTS-96 59 D.2 MODIFICATION OF IEEE-RTS-96 61 D.3 SYSTEM LOAD 62 D.4 WIND POWER GENERATION 64 D.5 NET LOAD 85 D.6 GEMERATORS 86 E. UNIT COMMITMENT BY DYNAMIC PROGRAMMING 89 E.1 FORMULATION 90 E.2 FORWARD DP APPROACH 92 F. DIFFERENCE BETWEEN THE PROPOSED METHOD AND PREVIOUS SHORT-TERM ADEQUACY STUDY 95 ABSTRACT IN KOREAN 97Docto

Near-IR Cavity-Dumped Femtosecond Optical Parametric Oscillator and the Frenkel Exciton Dynamics in J-aggregates

Docto

Transient Absorption Anisotropy Study of Ultrafast Energy Transfer in Porphyrin Monomer, Its Direct Meso-Meso Coupled Dimer and Trimer and Building a Tunable Femtosecond Laser

Maste

TDD 시스템에서 kalman 필터를 이용한 MIMO-OFDM 하향링크 채널 예측 기법

학위논문(석사) - 한국정보통신대학교 : 공학부, 2007.2, [ x, 45 p. ]Multiple-input multiple-output (MIMO) technique combined with orthogonal frequency division multiplexing (OFDM) has been considered as a key technology for next-generation wireless communication systems due to its potential of achieving high data rates and mitigating the hostile channel selectivity. In particular, MIMO downlink systems, such as beamforming or precoding system provide higher link capacity and simplify the receiver with channel state information (CSI) at the transmitter. In order to obtain CSI at the transmitter, a feedback from the receiver can be used when the up- and downlink channels are uncorrelated. In time-division duplex(TDD) systems, CSI for downlink can be obtained from uplink channel using reciprocity. However, the CSI from uplink is not accurate enough to keep track of the continuously varying channel characteristic in downlink period. A few channel prediction schemes, such as linear prediction and second order extrapolation are proposed to overcome the time difference between up- and downlink for TDD systems. Generally, second order extrapolation outperforms linear prediction in noiseless environment. However, second order extrapolation might have even worse performance than linear prediction because of noisy measurement data. Thus, a channel predictor which can resolve these problems due to outdated and imperfect CSI, is necessary. In this thesis, a MIMO-OFDM downlink channel prediction technique based on Kalman filter is proposed for TDD systems. The proposed method consists of three procedures: MMSE channel estimation, Kalman filtering and prediction, and linear interpolation. Kalman filter is employed to filter the estimated channel and to predict the next channel sample to determine the precoding weights. Simulation results of the proposed scheme based on IEEE802.16e system demonstrate that the proposed method improves the bit error rate (BER) performance significantly.한국정보통신대학교 : 공학부

Carfilzomib in addition to lenalidomide and dexamethasone in Asian patients with RRMM outside of a clinical trial

Carfilzomib, lenalidomide, and dexamethasone (KRd) effectively improve survival in patients with relapsed and refractory multiple myeloma (RRMM). However, the outcome of KRd treatment in Asian patients reflecting a general RRMM population outside of a clinical trial has not been reported. Fifty-five RRMM patients who were treated with carfilzomib in combination with Rd from the time of the first approval of KRd in the Republic of Korea were analyzed. The median age was 61 years. The percentage of patients with an ECOG performance status >= 3, creatinine clearance < 50 mL/min, high-risk cytogenetics, and >= 4 lines of prior treatment were 9%, 22%, 31%, and 27%, respectively. Forty-one patients started treatment with KRd, whereas the remaining 14 patients (25%) were added carfilzomib during the Rd treatment. In the whole cohort, the overall response rate was 73% and progression-free survival was 8.8 months. The addition of carfilzomib in patients who were refractory or had disease progression during Rd treatment reattained a response in half of the patients. The advantage of carfilzomib with Rd was significant in patients in the first relapse. Toxicity profile was acceptable, excluding severe infections. Carfilzomib in combination with Rd is effective and has a reasonable adverse event rate in Asian patients with RRMM