1384 IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 25, NO. 3, AUGUST 2010 Application of a Joint Deterministic-Probabilistic Criterion to Wind Integrated Bulk Power System Planning Roy Billinton, Life Fellow, IEEE, Yi Gao, Student Member, IEEE, and Rajesh Karki, Senior Member, IEEE Abstract—The basic objective of bulk power system planning is to develop the system as economically as possible while maintaining an acceptable level of service reliability. The traditional methods used by system planners to maintain acceptable bulk power system reliability are challenged in the present move to incorporate higher wind power penetration levels. Combining deterministic consider- ations with probabilistic assessment in order to evaluate the quan- titative system risk and conduct bulk power system planning has therefore become increasingly necessary and important in recent years. This paper examines the capacity value of wind generation using various approaches and the utilization of this value under the deterministic criterion. The application of a joint deterministic-probabilistic criterion for bulk system expansion planning in wind integrated systems is presented. The application of the conventional deterministic , the basic probabilistic and the joint deterministic-probabilistic criteria is illustrated in a wind integrated test system in this paper. Index Terms—Bulk power system, joint deterministic and prob- abilistic criterion, planning, wind capacity credit, wind energy. I. INTRODUCTION T HE addition of wind generation to bulk power systems is increasing rapidly throughout the world. Unlike conven- tional generation sources, wind power is variable due to its in- termittent and diffuse nature and traditional planning methods will have to adapt to ensure bulk power system reliability levels are maintained as wind power penetration levels increase. The deterministic planning criterion has been used by many electric power utilities for many years due to attractive charac- teristics such as, simple implementation, straightforward under- standing, assessment and judgment. The criterion has gen- erally resulted in acceptable security levels, but in its basic sim- plest form does not provide an assessment of the actual system reliability as it does not incorporate the probabilistic nature of system behavior and component failures. There is a growing interest in combining deterministic con- siderations with probabilistic assessment in order to evaluate Manuscript received June 11, 2009; revised December 11, 2009. First pub- lished January 29, 2010; current version published July 21, 2010. Paper no. TPWRS-00446-2009. The authors are with the Department of Electrical and Computer Engineering, University of Saskatchewan, Saskatoon, SK S7N 5A9, Canada (e-mail: roy. billinton@usask.ca; yig189@mail.usask.ca; rajesh.karki@usask.ca). Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/TPWRS.2009.2039652 the quantitative system risk and conduct bulk power system planning. A relatively new approach that incorporates determin- istic and probabilistic considerations in a single risk assessment framework has been designated as the joint deterministic-prob- abilistic (D-P) approach [1]. This paper extends this approach to wind integrated bulk power system planning. This paper examines the capacity value of wind generation using various approaches and how this capacity value can be utilized under a deterministic criterion. The application of capacity credit in the conventional approach is the first step in the application of the D-P method. Factors such as wind farm location, wind farm correlation levels, and installed wind capacity are considered in the studies described in this paper. The paper also illustrates the traditional deterministic criterion (D), the basic probabilistic (P) criterion and the D-P criterion by application to a bulk power system incorporating wind energy. II. STUDY SYSTEM AND METHODS A. Study Methods In a basic deterministic (D) approach, using the cri- terion, the system should be able to withstand the loss of any single element at the peak load condition. An criterion is used in some systems. In the probabilistic (P) approach, the system risk should not exceed a designated criterion value (Rc). In the D approach, the likelihood of the designated single ele- ment failing is not included in the analysis, while in the P ap- proach this likelihood is included together with similar proba- bilities for all the elements in the system to calculate the system risk (Rc). The joint deterministic-probabilistic (D-P) approach includes both deterministic and probabilistic criteria and is de- fined as follows: The system is required to satisfy a deterministic criterion and also meet an acceptable risk criterion (Pc) under the designated outage condition [1]. The D-P tech- nique provides a bridge between the accepted deterministic and probabilistic methods. The basic deterministic technique results in a variable risk level under each critical outage condi- tion. This is particularly true when the critical outage switches from a transmission element to a generating unit or vice versa. In the D-P approach the system must first satisfy the D crite- rion. The system risk given that the critical element has failed must then be equal to or less than a specified probabilistic risk criterion (Pc). If this risk is less than or equal to the criterion value, the D and D-P approaches provide the same result. If the risk exceeds this value then the load must be reduced to meet 0885-8950/$26.00 © 2010 IEEE