1990

Interruptible load considerations in spinning reserve assessment of isolated and interconnected generating systems

Chowdhury, N.; Billinton, R.;
Power Syst. Res. Group, Saskatchewan Univ., Saskatoon, Sask.

This paper appears in: Generation, Transmission and Distribution, IEE Proceedings C
Issue Date: Mar 1990
Volume: 137 Issue:2
On page(s): 159 - 167
ISSN: 0143-7046
INSPEC Accession Number: 3606872
Date of Current Version: 06 八月 2002

Abstract
The authors present a technique which includes interruptible loads in the probabilistic assessment of the operating reserve in isolated and interconnected generating systems. This technique is then used to evaluate the magnitude and corresponding maximum allowable time delay of load interruption required to reduce the unit commitment risk in the absence of other capacity adjustments. They also present a probabilistic technique which can be used to evaluate the inherent interruptible load carrying capability of an isolated and interconnected generating system which exists without having to commit any extra units other than those required to carry the firm load. The study provides an insight into load interruption and its effect on the system risk. The techniques developed are illustrated by numerical examples. These techniques can be used in short and medium term operational planning

Electric Power Systems Research
Volume 18, Issue 2, March 1990, Pages 99–103

Microprocessor based on-line assessment of the operational reliability of a longitudinal power supply system * A. Chakrabarti, * A.K. Mukhopadhyay * Electrical Machines and Power System, Department of Applied Physics, Faculty of Technology, University of Calcutta, 92 Acharya P.C. Road, Calcutta 700 009 India * Received 23 October 1989. Available online 13 February 2003. * http://dx.doi.org.ezlibproxy1.ntu.edu.sg/10.1016/0378-7796(90)90012-R, How to Cite or Link Using DOI * Permissions & Reprints

Abstract
The maximum power transfer criterion in a tie-line of a typical longitudinal power supply system at critical stages of the reactive and real power limits with and without voltage control at the receiving end has been investigated. Microprocessor software is developed for on-line assessment of the system reliability at various stages of power transfer and to actuate the audio-visual alarm and trip at corresponding limits. A stability criterion associated with a voltage stable state of a week tie-line has been incorporated in the software for application in a basic model of a real power system.

Risk constrained economic load dispatch in interconnected generating systems

Chowdhury, N. ; Billinton, R. ;
Saskatchewan Univ., Saskatoon, Sask.

This paper appears in: Power Systems, IEEE Transactions on
Issue Date : Nov 1990
Volume : 5 , Issue:4
On page(s): 1239 - 1247
ISSN : 0885-8950
INSPEC Accession Number: 3827413
Digital Object Identifier : 10.1109/59.99375
Date of Current Version : 06 八月 2002
Sponsored by : IEEE Power & Energy Society
Abstract
A risk-constrained unit loading technique for interconnected systems is presented which utilizes a least-costly deviation for economic load dispatch to satisfy the risk criteria. The technique is developed on the basis of each area in a multi-area configuration fulfilling one of two different response risk criteria. The technique is illustrated with numerical examples. Risk-constrained economic loading schedules have been developed using reloading steps of 1 MW and 5 MW. In an actual system, other reloading steps should be tried in order to meet the specific needs of the system in terms of operating economy and computation time

Export/import of spinning reserve in interconnected generation systems

Chowdhury, N.; Billinton, R.;
Saskatchewan Univ., Saskatoon, Sask.
This paper appears in: Power Systems, IEEE Transactions on
Issue Date: Feb 1991
Volume: 6 Issue:1
On page(s): 43 - 50
ISSN: 0885-8950
Cited by : 2
INSPEC Accession Number: 3893377
Digital Object Identifier: 10.1109/59.131046
Date of Current Version: 06 八月 2002
Sponsored by: IEEE Power & Energy Society

Abstract
Interconnected power systems may import energy and/or purchase spinning reserves from neighbors in order to reduce risk. A probabilistic technique is presented to assess import and/or spinning reserve purchase requirements of interconnected systems in order to overcome the effects of inadequate operating capacity on unit commitment risk. A unit commitment technique which can include options of spinning reserve purchase/sale is presented. A method of assessing the portion of the running cost in interconnected power systems due to export/import and purchase of spinning reserve is also illustrated

Operating reserve and reliability analysis of the Taiwan power system

Hsu, Y.-Y.; Lee, Y.-S.; Jien, J.-D.; Liang, C.C.; Chen, K.-K.; Lai, T.-S.; Lee, T.-E.;
Dept. of Electr. Eng., Coll. of Eng., Nat. Taiwan Univ., Taipei
This paper appears in: Generation, Transmission and Distribution, IEE Proceedings C
Issue Date: Sep 1990
Volume: 137 Issue:5
On page(s): 349 - 357
ISSN: 0143-7046
INSPEC Accession Number: 3781441
Date of Current Version: 06 八月 2002

Abstract
A probabilistic approach to examining the effect of operating reserve on the reliability and security of the Taiwan power system is developed. To evaluate the probability of failure to carry load in system operation, an extension of the original PJM (Pennsylvania-New Jersey-Maryland) method is presented. System security is analysed using the reliable emergency output power (REOP) index. The proposed methods are applied to evaluate the reliability and security of the Taiwan power system using the operating records of the past five years. 32 load patterns are examined for each year to cover the different seasons of the year, the different days of the week and the peak and off-peak periods of the day. The factors affecting system reliability and security such as the amount and type of spinning reserves and the availability of rapid-start units are extensively examined. It is found that the presented probabilistic approach can provide valuable information which can assist the system operators to reach a secure and reliable, as well as economical, unit commitment strategy

Unit commitment risk with sequential rescheduling

Lee, F.N.; Chen, Q.; Breipohl, A.;
Sch. of Electr. Eng. & Comput. Sci., Oklahoma Univ., Norman, OK
This paper appears in: Power Systems, IEEE Transactions on
Issue Date: Aug 1991
Volume: 6 Issue:3
On page(s): 1017 - 1023
ISSN: 0885-8950
Cited by : 1
INSPEC Accession Number: 4027495
Digital Object Identifier: 10.1109/59.119241
Date of Current Version: 06 八月 2002
Sponsored by: IEEE Power & Energy Society

Abstract
Rescheduling decisions in power system operation are often made to commit additional generating capacity to meet the system obligation of load plus spinning reserve. These are based on the observation of some events (e.g. unit forced outage) which lead to possible capacity deficiency. A new concept is presented of unit commitment risk analysis which explicitly models the stochastic sequence of events associated with rescheduling decisions. This concept is compared with that of the PJM method via a simple example. Based on the concept of rescheduling, a stochastic model is proposed for risk analysis, and this model is illustrated via simulation results

A reliability test system for educational purposes-spinning reserve studies in isolated and interconnected systems

Chowdhury, N.; Billinton, R.;
Saskatchewan Univ., Saskatoon, Sask.
This paper appears in: Power Systems, IEEE Transactions on
Issue Date: Nov 1991
Volume: 6 Issue:4
On page(s): 1578 - 1583
ISSN: 0885-8950
Cited by : 4
INSPEC Accession Number: 4079654
Digital Object Identifier: 10.1109/59.117005
Date of Current Version: 06 八月 2002
Sponsored by: IEEE Power & Energy Society

Abstract
Operating reserve in a system is required to make the system capable of handling unforeseen load changes and possible outages of generation. The basic results of an assessment of operating reserve requirements in a small reliability test system are presented. Results are presented for both isolated and interconnected configurations. The results provide a basic understanding of probabilistic assessment of operating reserve requirements and can be included in a power system reliability teaching program

Energy method of spinning reserve assessment in interconnected generation systems

Chowdhury, N.;
Power Syst. Res. Group, Saskatchewan Univ., Saskatoon, Sask.
This paper appears in: Power Systems, IEEE Transactions on
Issue Date: Aug 1993
Volume: 8 Issue:3
On page(s): 865 - 872
ISSN: 0885-8950
INSPEC Accession Number: 4581882
Digital Object Identifier: 10.1109/59.260917
Date of Current Version: 06 八月 2002
Sponsored by: IEEE Power & Energy Society

Abstract
A probabilistic technique for assessing spinning reserve requirements in interconnected systems has been published. The technique, the two risks concept, is based on capacity assistance and, therefore, does not deal with some of the essential system issues pertaining to unit size and lead time in a consistent manner as far as the spinning reserve assessment is concerned. An energy based technique to assess spinning reserve requirements in interconnected systems is presented. The proposed technique responds to unit size and lead time in a direct way. Two test systems and a hypothetical system are utilized to provide numerical examples

Operating reserve risk assessment in composite power systems

Guangbin Lian; Billinton, R.;
Power Syst. Res. Group, Saskatchewan Univ., Saskatoon, Sask.
This paper appears in: Power Systems, IEEE Transactions on
Issue Date: Aug 1994
Volume: 9 Issue:3
On page(s): 1270 - 1276
ISSN: 0885-8950
Cited by : 4
INSPEC Accession Number: 4768457
Digital Object Identifier: 10.1109/59.336140
Date of Current Version: 06 八月 2002
Sponsored by: IEEE Power & Energy Society
Abstract
This paper presents an operating reserve risk assessment procedure for composite generation and transmission systems. This method is utilized to study risk constrained unit commitment under various system operating conditions. The unit commitment studies are done on composite generation and transmission system and recognize common mode failures of transmission lines and station initiated outages. The procedure presented in this paper incorporates a physical appreciation of the effect of transmission lines and station elements on the composite system operating risk index and therefore on the units committed for operation. This procedure is illustrated by application to the hypothetical test system designated as the RBTS

Composite system spinning reserve assessment in interconnected systems

Khan, M.E.; Billinton, R.;
Dept. of Electr. & Comput. Syst. Eng., Monash Univ., Clayton, Vic.
This paper appears in: Generation, Transmission and Distribution, IEE Proceedings-
Issue Date: May 1995
Volume: 142 Issue:3
On page(s): 305 - 309
ISSN: 1350-2360
INSPEC Accession Number: 4967936
Digital Object Identifier: 10.1049/ip-gtd:19951716
Date of Current Version: 06 八月 2002
Sponsored by: IET

Abstract
Deterministic methods to evaluate unit commitment and spinning reserve requirements cannot explicitly recognise the stochastic nature of a power system. Probabilistic techniques can, however, be used to incorporate a wide range of stochastic system parameters. The usual techniques of probabilistic unit commitment in an interconnected power system consider the tie-line constraints but not the transmission facilities within the systems. In a real power system, the transmission facilities within the systems have limits and do fail. Units committed from only probabilistic generation studies, therefore, provide optimistic values. In the paper, the usual techniques of unit commitment are extended to calculate a risk value from a composite system point of view. The effect on the risk value of rapid start and hot reserve units are considered

Spinning reserve allocation using response health analysis

Fotuhi-Firuzabad, M.; Billinton, R.; Aboreshaid, S.;
Power Syst. Res. Group, Saskatchewan Univ., Saskatoon, Sask.
This paper appears in: Generation, Transmission and Distribution, IEE Proceedings-
Issue Date: Jul 1996
Volume: 143 Issue:4
On page(s): 337 - 343
ISSN: 1350-2360
INSPEC Accession Number: 5359185
Digital Object Identifier: 10.1049/ip-gtd:19960312
Date of Current Version: 06 八月 2002
Sponsored by: IET

Abstract
An approach to evaluate the degree of system well-being in the responding capability of a generation system is presented. The overall well being of a generation system in terms of its responding capability is identified as being healthy, marginal and at risk. A risk criterion, designated as the `generating system response state risk' (GSRSR), is used to determine the generating unit loading schedule. The committed units are loaded such that a specified GSRSR, an acceptable response health probability or both are satisfied. The concept of multiple criteria provides the system operator with considerable flexibility in selecting a meaningful reliability level for load dispatch. These concepts are illustrated by application to the IEEE reliability test system (IEEE-RTS)

Reliability analysis for hydrothermal generating systems including the effect of maintenance scheduling

Juan, J.; Ortega, I.;
E.T.S. Ingenieros Ind., Madrid
This paper appears in: Power Systems, IEEE Transactions on
Issue Date: Nov 1997
Volume: 12 Issue:4
On page(s): 1561 - 1568
ISSN: 0885-8950
Cited by : 5
INSPEC Accession Number: 5749359
Digital Object Identifier: 10.1109/59.627859
Date of Current Version: 06 八月 2002
Sponsored by: IEEE Power & Energy Society

Abstract
Usually, power system reliability indicators are obtained for one year periods, and must take into account maintenance requirements for thermal generating units. This paper describes an efficient method for the calculation of the two most common power system reliability indicators: LOLE (loss of load expectation) and EENS (expected value of energy not served), in the case of electric systems including generation units with limits on energy generation (hydropower plants with a variable amount of available water). The method is based on transforming the initial load curve into a thermal load curve, which enables one to separate completely the hydrothermal and the thermal power systems, thereby facilitating both reliability evaluations and maintenance scheduling

Probabilistic evaluation of the effect of maintenance on reliability. An application [to power systems]

Endrenyi, J.; Anders, G.J.; Leite da Silva, A.M.;
Ontario Hydro, Toronto, Ont.
This paper appears in: Power Systems, IEEE Transactions on
Issue Date: May 1998
Volume: 13 Issue:2
On page(s): 576 - 583
ISSN: 0885-8950
Cited by : 8
INSPEC Accession Number: 5904091
Digital Object Identifier: 10.1109/59.667385
Date of Current Version: 06 八月 2002
Sponsored by: IEEE Power & Energy Society
Abstract
The purpose of maintenance is to extend equipment lifetime, or at least the mean time to the next failure. While too little maintenance may have very costly consequences, maintenance, too, incurs expenditures and it may not be economical to perform it too frequently. Therefore, the two costs must be balanced. In the past, attempts to approximate this balance have often been based on trial and error. In this paper, a probabilistic model is proposed for the purpose, and a computer program based on this model is described. The model provides a quantitative connection between reliability and maintenance, a link missing in the heuristic approaches. The component ageing process is modelled, and the mean and distribution of the remaining life to failure are predicted for any stage of ageing. The method is applied to a practical example

Capacity reserve assessment using system well-being analysis

Billinton, R.; Karki, R.;
Power Syst. Res. Group, Saskatchewan Univ., Saskatoon, Sask.
This paper appears in: Power Systems, IEEE Transactions on
Issue Date: May 1999
Volume: 14 Issue:2
On page(s): 433 - 438
ISSN: 0885-8950
References Cited: 6
Cited by : 15
INSPEC Accession Number: 6248894
Digital Object Identifier: 10.1109/59.761861
Date of Current Version: 06 八月 2002
Sponsored by: IEEE Power & Energy Society
Abstract
Deterministic methods are widely used in operating reserve assessment and in small isolated power system capacity planning. These approaches do not normally include any explicit recognition of system risk and do not provide comparable risks for systems of different size or composition. Many large power systems, therefore, use probabilistic methods for generation adequacy evaluation. The reluctance to utilize the existing probabilistic techniques in both large and small systems dictates a need to create a bridge between the two different approaches. This paper presents a new probabilistic method designated as `system well-being analysis', which incorporates the accepted deterministic criteria in the definition of `healthy' and `marginal' power system states. This paper illustrates methodologies to evaluate the system well-being indices of practical systems and describes how they can be used in the assessment of power system capacity reserves

Electric Power Systems Research
Volume 53, Issue 2, 1 February 2000, Pages 133–138

A fuzzy-based approach for generation system reliability evaluation * Seshamani Narasimhana, * Sohrab Asgarpoorb, * a J.D. Edwards World Source Company, One Technology Way, Denver, CO 80237, USA * b 209N Walter Scott Engineering Center, Department of Electrical Engineering, University of Nebraska, Lincoln, NE 68588-0511, USA * Received 10 October 1998. Accepted 27 April 1999. Available online 14 December 1999. * http://dx.doi.org.ezlibproxy1.ntu.edu.sg/10.1016/S0378-7796(99)00045-0, How to Cite or Link Using DOI * Permissions & Reprints

Abstract
A new method for calculating generation system reliability using fuzzy mathematics is presented here. In reliability evaluation of power systems, a membership function can be provided to represent the uncertainties and inaccuracies in the failure rates and repair rates of generating units. The basic unit addition recursive algorithm is modified to represent these uncertainties along with uncertainties in system load as fuzzy data. Loads are represented as clusters to overcome the difficulty of large computational time requirements. A computer program has been developed in C language to include all aforementioned factors. The program was tested with the IEEE Reliability Test System on an IBM RS/6000 workstation. Several cases were analyzed and results are presented. The algorithm developed computes reliability indices such as loss of load probability (LOLP) and the expected unserved energy (EWE) which are viewed as possibility distributions.

Electric Power Systems Research
Volume 56, Issue 1, 5 October 2000, Pages 81–88

A reliability framework for generating unit commitment * Roy Billinton, * Mahmud Fotuhi-Firuzabad * Power Systems Research Group, Department of Electrical Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, Sask., Canada S7N 5A9 * Received 22 March 1999. Accepted 1 March 2000. Available online 14 September 2000. * http://dx.doi.org.ezlibproxy1.ntu.edu.sg/10.1016/S0378-7796(00)00104-8, How to Cite or Link Using DOI * Permissions & Reprints

Abstract
Operating reserve assessment should become increasingly important in the new utility environment in which system supply services will be assigned a value and purchased in a competitive market. It is therefore important from an educational point of view that students appreciate the techniques and procedures, which are used, and those, which can be used to quantitatively assess operating, reserve requirements. A technique is presented in this paper which provides a reliability framework for unit commitment in an electric power system using well-being analysis. The well-being framework provides the opportunity to consider both deterministic and probabilistic approaches and to appreciate the weaknesses associated with using the deterministic approach or a single risk index. The study results presented can be used to teach basic power system reliability evaluation and assessment. These studies provide a useful pedagogical framework for further development.

Interruptible load analysis using sequential Monte Carlo simulation

Chen, H.; Billinton, R.;
Power Syst. Res. Group, Saskatchewan Univ., Saskatoon, Sask.
This paper appears in: Generation, Transmission and Distribution, IEE Proceedings-
Issue Date: Nov 2001
Volume: 148 Issue:6
On page(s): 535 - 539
ISSN: 1350-2360
Cited by : 1
INSPEC Accession Number: 7099683
Digital Object Identifier: 10.1049/ip-gtd:20010582
Date of Current Version: 07 八月 2002
Sponsored by: IET

Abstract
Electric utilities are increasingly examining cost-effective opportunities to utilise demand-side management initiatives, such as interruptible contracts to reduce the need for additional capacity. Techniques are presented for conducting interruptible load analysis using sequential Monte Carlo Simulation. A bisection search approach was developed to effectively determine the interruptible load carrying capability. An index, designated the avoidable additional generating capacity, is proposed and a procedure to calculate it is presented. Numerical studies were performed to indicate the possible applications of the proposed techniques

Including uncertainty in LOLE calculation using fuzzy set theory

Kim, J.-O.; Singh, C.;
Dept. of Electr. Eng., Hanyang Univ., Seoul
This paper appears in: Power Systems, IEEE Transactions on
Issue Date: Feb 2002
Volume: 17 Issue:1
On page(s): 19 - 25
ISSN: 0885-8950
References Cited: 8
Cited by : 12
INSPEC Accession Number: 7180895
Digital Object Identifier: 10.1109/59.982188
Date of Current Version: 07 八月 2002
Sponsored by: IEEE Power & Energy Society

Abstract
This paper presents a conceptual possibilistic approach using fuzzy set theory to manage the uncertainties in the reliability input data of real power systems. In this paper, an algorithm is introduced to calculate the possibilistic reliability indices according to the degree of uncertainty in the given data. The probability distribution function can be transformed into an appropriate possibilistic representation using the probability-possibility consistency principle (PPCP) algorithm. In this algorithm, the transformation is performed by making a compromise between the transformation consistency and the human experience. Fuzzy classification theory is applied to reduce the number of load data points. The fuzzy classification method determines the closeness of load data points by assigning them to various clusters and then determining the distance between the clusters. The IEEE-RTS with 32-generating units is used to demonstrate the capability of the proposed algorithm

An electricity market with a probabilistic spinning reserve criterion

Bouffard, F.; Galiana, F.D.;
Dept. of Electr. & Comput. Eng., McGill Univ., Montreal, Que., Canada
This paper appears in: Power Systems, IEEE Transactions on
Issue Date: Feb. 2004
Volume: 19 Issue:1
On page(s): 300 - 307
ISSN: 0885-8950
References Cited: 12
Cited by : 37
INSPEC Accession Number: 7926557
Digital Object Identifier: 10.1109/TPWRS.2003.818587
Date of Current Version: 19 二月 2004
Sponsored by: IEEE Power & Energy Society

Abstract
This paper addresses the problem of reliability-constrained market-clearing in pool-based electricity markets with unit commitment. In general, probabilistic reliability criteria that implicitly set the reserve requirement are defined by the loss-of-load probability and by the expected load not served. As the computation of such metrics is complicated by their nonlinear and combinatorial nature, we introduce the notion of hybrid metrics based on the probabilities of loss-of-load due to single and double generation outages only. The reliability-constrained market-clearing problem can then be formulated as a mixed-integer linear program and solved with large-scale commercial solvers. Numerical tests with data from the IEEE Reliability Test System indicate that the new method is computationally efficient and produces market-clearing results with the desired probabilistic characteristics.

Reliability Constrained Unit Commitment Using Simulated Annealing

Simopoulos, D.N.; Kavatza, S.D.; Vournas, C.D.;
Sch. of Electr. & Comput. Eng., Univ. of Athens
This paper appears in: Power Systems, IEEE Transactions on
Issue Date: Nov. 2006
Volume: 21 Issue:4
On page(s): 1699 - 1706
ISSN: 0885-8950
Cited by : 8
INSPEC Accession Number: 9160529
Digital Object Identifier: 10.1109/TPWRS.2006.881128
Date of Current Version: 30 十月 2006
Sponsored by: IEEE Power & Energy Society

Abstract
This paper proposes a new method for the incorporation of the unit unavailability and the uncertainty of the load forecast in the solution of the short-term unit commitment problem. The above parameters are taken into account in order to assess the required spinning reserve capacity at each hour of the dispatch period, so as to maintain an acceptable reliability level. The unit commitment problem is solved by a simulated annealing algorithm resulting in near-optimal unit commitment solutions. The evaluation of the required spinning reserve capacity is performed by implementing reliability constraints, based on the expected unserved energy and loss of load probability indexes. In this way, the required spinning reserve capacity is effectively scheduled according to the desired reliability level. Numerical simulations have proven the efficiency of the proposed method

Online short-term reliability evaluation using a fast sorting technique

Liu, H.; Sun, Y.; Cheng, L.; Wang, P.; Xiao, F.;
Tsinghua Univ., Beijing
This paper appears in: Generation, Transmission & Distribution, IET
Issue Date: January 2008
Volume: 2 Issue:1
On page(s): 139 - 148
ISSN: 1751-8687
Cited by : 7
INSPEC Accession Number: 9944205
Digital Object Identifier: 10.1049/iet-gtd:20070340
Date of Current Version: 21 一月 2008
Sponsored by: Institution of Engineering and Technology

Abstract
To consider time varying system operating conditions and operating reserve units, the online short-term reliability of a power system is investigated. Real-time system reliability based on the online operation data provided by the SCADA/EMS/WAMS is assessed using time- dependent state probabilities of components. Considering both speed and accuracy requirements, a fast sorting technique (FST) is proposed to quickly select the required number of system states in descending order probability. The number of computations and comparisons used in the evaluation is minimum. The relative accuracy of a given reliability index is denned as the stopping rule for the evaluation. As only a small number of system states are required to achieve the high accuracy of the short-term reliability indices when using the FST, the evaluation can be performed in an online environment. The proposed evaluation technique is illustrated by the application to the IEEE-RTS and China Southern Power Grid.

Operational reliability assessment of power systems considering condition-dependent failure rate

Sun, Y.; Wang, P.; Cheng, L.; Liu, H.;
Dept. of Electr. Eng., Tsinghua Univ., Beijing, China
This paper appears in: Generation, Transmission & Distribution, IET
Issue Date: January 2010
Volume: 4 Issue:1
On page(s): 60 - 72
ISSN: 1751-8687
INSPEC Accession Number: 11020628
Digital Object Identifier: 10.1049/iet-gtd.2009.0006
Date of Current Version: 22 十二月 2009
Sponsored by: Institution of Engineering and Technology

Abstract
Failure rate of a system component is usually assumed to be constant in conventional reliability evaluation of power systems. It has been realised from the real-time operation that a component will experience more failures during heavy loading condition than those during light loading condition, which means that the failure rate of a component in real-time operation is not constant and varies with loading condition. In order to evaluate system operational reliability related to load condition, the factors affected condition-dependent failure rate (CDFR) are investigated and a basic CDFR model is proposed in this study. In predictive operational reliability study, equipment loading condition for a given load period is determined using AC power flow based on the corresponding load level with considering load uncertainty. A four-state model has been proposed to represent a system component. The equations for determining the probability of each state for the four-state model have been derived. A technique based on these equations and models has been developed to evaluate operational and annual reliability indices of components, load points and system. The IEEE-RTS has been analysed to illustrate the proposed models and technique.

Optimising probabilistic spinning reserve using an analytical expected-energy-not-supplied formulation
窗体底端

Wang, M.Q.; Gooi, H.B.; Chen, S.X.;
Sch. of EEE, Nanyang Technol. Univ. (NTU), Singapore, Singapore
This paper appears in: Generation, Transmission & Distribution, IET
Issue Date: July 2011
Volume: 5 Issue:7
On page(s): 772 - 780
ISSN: 1751-8687
INSPEC Accession Number: 12116465
Digital Object Identifier: 10.1049/iet-gtd.2010.0805
Date of Current Version: 12 八月 2011
Sponsored by: Institution of Engineering and Technology

Abstract
Spinning reserve (SR) is an important resource, which can protect power systems without involuntary load shedding. The SR requirement needs to be assigned appropriately. In this study, a probabilistic method is used to optimise the SR requirement. The SR amount is determined by simultaneously optimising the operating cost, reserve cost and the expected interruption cost. Tremendous computational requirements introduced by the expected-energy-not-supplied (EENS) calculation make the major impediment to the optimisation solutions. In this study, a multi-step method is proposed to overcome the computation intractability of the EENS problem. The EENS of each optimisation period is analytically formulated as a piecewise linear function of system spinning reserve of that period. The parameters of the piecewise linear function are derived from the capacity outage probability table, which is established based on the exogenous unit schedule. The efficiency and validity of the proposed method is verified using the IEEE-RTS system.

Spinning Reserve Estimation in Microgrids

Wang, M.Q.; Gooi, H.B.;
Sch. of Electr. & Electron. Eng., Nanyang Technol. Univ., Singapore, Singapore
This paper appears in: Power Systems, IEEE Transactions on
Issue Date: Aug. 2011
Volume: 26 Issue:3
On page(s): 1164 - 1174
ISSN: 0885-8950
References Cited: 24
INSPEC Accession Number: 12175136
Digital Object Identifier: 10.1109/TPWRS.2010.2100414
Date of Publication: 28 一月 2011
Date of Current Version: 22 七月 2011
Sponsored by: IEEE Power & Energy Society

Abstract
In this paper, a probabilistic methodology for estimating spinning reserve requirement in microgrids is proposed. The spinning reserve amount is determined by a tradeoff between reliability and economics. The unreliability of units and uncertainties caused by load and nondispatchable units are both considered. In order to reduce computation burden, various uncertainties are aggregated. A multistep method is proposed to efficiently consider the combinatorial characteristic of unit outage events. The computation efficiency of spinning reserve calculations can be greatly improved. The optimization is solved by mixed integer linear programming (MILP). Two case studies are carried out to illustrate the proposed method. Their results and discussions are also presented.