انتخاب مشتری قابلیت اطمینان تامین چرخشی رزرو و تخصیص هزینه با استفاده از تجزیه و تحلیل رفاه

A novel pool-based market-clearing algorithm for spinning reserve (SR) procurement and the cost allocation associated with provision of spinning reserve among customers (DisCos) is developed in this paper. Rational buyer market model is used to clear energy and spinning reserve markets in the proposed algorithm. This market model gives DisCos the opportunity to declare their own energy requirement together with their desired reliability levels to the ISO and also they can participate in the SR market as a interruptible load. The DisCos’ desired reliability levels are selected from a hybrid deterministic/probabilistic framework designated as the system well-being model. Using the demand of each DisCo and its associated desired reliability level, the overall desired system reliability level is determined. The market operator then purchases spinning reserve commodity from the associated market such that the overall desired system reliability level is satisfied. A methodology is developed in this paper to fairly allocate the cost associated with providing spinning reserve among DisCos based on their demands and desired reliability levels. An algorithm is also presented in this paper for implementing the proposed approach. The effectiveness of the proposed technique is examined using the IEEE-RTS.

Power system operators must maintain a certain amount of spinning reserve at all times to account for sudden loss of generating capacity or system load fluctuation [1] and [2]. In a traditional power system, the decision for providing the required spinning reserve is made centrally and the cost associated with the provided spinning reserve is allocated among customers based on their load levels. Since the past decade, power industries worldwide have been going through a process of restructuring in order to introduce commercial incentives in generation, transmission and distribution. The reforms are achieved through a clear separation between production and sale of electricity, and network operations [3]. A key point in the competitive environment for the power industry is that the customer must be at the center of any business strategy. Deregulation has made it possible for consumers to select their suppliers based on cost effectiveness. In a mature market they must also have a say in reliability matter, mostly by making decisions on the reliability level of supply for which they want to receive and are willing to pay [4] and [5]. Therefore, not only can the consumers bid their load levels and prices, but also they can declare their desired reliability levels for the supply they receive [4]. Both deterministic and probabilistic approaches can be used to establish spinning reserve requirements. The essential disadvantage of the deterministic criteria is that they do not respond to the many factors that influence the actual risk in the system. Utilization of probabilistic techniques enables the random nature of system components and load behavior to be included in a consistent manner. Ref. [6] presents a probabilistic technique to determine the required spinning reserve in a traditional power system using the loss of load probability (LOLP) index. A probabilistic pool-based market-clearing algorithm is presented in Ref. [7] for application in electricity markets where generation scheduling is performed based not only on the prices of energy and reserve, but also on the reliabilities of generating units. In order to incorporate practical security considerations in operating reserve assessment and to alleviate the dilemma associated with the lack of sufficient information provided by probabilistic indices including difficulties in interpreting the risk index, a bridge was created between the deterministic methods and the prevalent probabilistic techniques using a system well-being model [8], [9], [10] and [11]. A hybrid probabilistic/deterministic method is presented in Refs. [8] and [9] using the well-being model to provide the requisite spinning reserve and its allocation in traditional power systems. Ref. [11] extends the application of the well-being framework to adequacy evaluation of composite systems in the competitive environment. Goel et al. [12] extended the well-being technique to determine the customer spinning reserve requirements based on desired reliability levels in a bilateral market model. A number of bulk load point indices are introduced in Ref. [12] for customers to recognize their reliability levels. A novel pool-based market-clearing algorithm for spinning reserve procurement and the cost allocation associated with providing spinning reserve among DisCos is developed in this paper using the well-being model. Rational buyer market model [3] is used to clear energy and spinning reserve markets in the proposed algorithm. In such a market, DisCos declare their desired reliability levels and purchase their requisite reserve in an ancillary services market based on pre-selected (desired) reliability levels. A methodology is developed to determine how each user (DisCo) contributes to the use of the procured spinning reserve. Once the contribution of different users is determined, the next step is to fairly implement provided spinning reserve among users based on their demands and desired reliability levels. The IEEE Reliability Test System (RTS) [13] is used to examine the effectiveness and applicability of the proposed algorithm and the results are presented and discussed.

This paper focuses on the development and implementation of a new methodology for spinning reserve procurement and cost allocation associated with provision of spinning reserve among DisCos in a pool-based market. This new tool permits the ISO to provide reliability differentiated services on an individual customer basis. In the proposed approach, energy and spinning reserve markets are sequentially cleared. In this market, DisCos declare their desired reliability levels and purchase their requisite reserve in an ancillary service market based on their preferred reliability levels. The DisCos’ desired reliability levels are selected from a hybrid deterministic/probabilistic framework designated as the system well-being model. An algorithm is developed to determine how each user contributes to the usage of procured spinning reserve based on the user's desired reliability level and its associated demand. Moreover, an implementing algorithm which is properly proportional to the proposed cost allocation scheme is suggested to implement various desired reliability levels of DisCos. The proposed algorithms were applied to the IEEE-RTS and the results are presented and discussed. A step-by-step procedure is illustrated to clarify the applicability of the proposed methodology. The impacts on spinning reserve allocation and as such the associated cost among DisCos of load level and desired reliability level of DisCos are also illustrated. Finally, a discussion is provided to illustrate how the choice of the customer desired level of reliability can be implemented.