A comprehensive strategy for transmission switching action in simultaneous clearing of energy and spinning reserve markets Rahmat Aazami a,b,⇑ , Mahmoud Reza Haghifam c , Farzad Soltanian b , Masoud Moradkhani b a Faculty of Engineering, Ilam University, Ilam, Iran b Department of Electrical Engineering, Ilam Branch, Islamic Azad University, Ilam, Iran c Faculty of Electrical and Computer Engineering, Tarbiat Modares University, Tehran, Iran article info Article history: Received 19 July 2013 Received in revised form 15 June 2014 Accepted 6 July 2014 Keywords: Transmission switching Stochastic programming Dynamic constraints abstract There is a great resolution calling for smart grids in recent years. Introduction of new technologies, that make the network ﬂexible and controllable, is a main part of smart grid concept and a key factor to its success. Transmission network as a part of system network has drawn less attention. Transmission switching as a new transmission service can release us from load shedding and remove the constraints’ violations. Transmission switching can provide economic beneﬁts compared to other control methods such as generation unit rescheduling or load shedding for contingency management. Utilizing a stochastic mix-integer nonlinear programming (SMINLP) model, transmission switching is used during contingencies and steady state to determine optimal required energy and reserve values. Stochastic joint energy and reserve markets with transmission switching considering dynamic con- straints has been proposed to minimize the cost of supplying load, security expenses. Considering dynamic constraints in proposed model avoid the occurrence of transient instability when opening the line in transmission switching action. A network reduction method based on modiﬁed Jacobean AC Newton–Raphson technique power ﬂow considering switchable line in technique is used for speeding up the calculation, efﬁciency and simplicity. To investigate the efﬁciency of the proposed strategy IEEE 14 bus test and IEEE 57 bus test system are studied. According to the obtained results, this strategy decreases energy and reserve marginal prices, as well as security cost. Ó 2014 Elsevier Ltd. All rights reserved. Introduction In the last decade, transmission network has been a passive player in electricity markets. Recently policies have been suggested to make transmission owners more active market participants. To attract more investments for developing smart transmis- sion networks and increasing their ﬂexibility and efﬁciency, recently policies have been suggested which provide ﬁnical incen- tives in transmission network investment. These policies included transmission switching, price biding for incremental transmission capacity and dispatchable transmission services in power markets. Transmission network services can provide ﬂexible control actions for contingency management [1–3,9–16]. An example in smart networks is switching the transmission lines for congestion management. Federal Energy Regulatory Commission orders 890 calls for bet- ter economic operations of the transmission grid. One part of the smart grid concept aims at making better use of the current infra- structure as well as additions to the grid that enable more sophis- ticated use of the network [1–3,9–16]. This study focuses on an idea that improves the use of the current infrastructure with employing transmission switching action. Transmission networks for bulk power ﬂow have been modeled as static systems, except during times of forced outages or mainte- nance [1–3,9–16]. This traditional view does not describe them as assets that operators have the ability to control. However in smart networks, switching transmission lines is a common practice with a mature technology; circuit breakers can open and close transmis- sion lines. Transmission switching may change the status of the power systems and where upon affect the power ﬂow in lines and voltage http://dx.doi.org/10.1016/j.ijepes.2014.07.032 0142-0615/Ó 2014 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. E-mail address: azami.rahmat@yahoo.com (R. Aazami). Electrical Power and Energy Systems 64 (2015) 408–418 Contents lists available at ScienceDirect Electrical Power and Energy Systems journal homepage: www.elsevier.com/locate/ijepes