ECE Department, University of Houston, Houston, TX 77004 School of Electrical Engineering and Computer Science, Peking University, Beijing, China
arXiv:1210.3252v1 [cs.CR] 10 Oct 2012
Abstract—Applications of cyber technologies improve the quality of monitoring and decision making in smart grid. These cyber technologies are vulnerable to malicious attacks, and compromising them can have serious technical and economical problems. This paper speciﬁes the effect of compromising each measurement on the price of electricity, so that the attacker is able to change the prices in the desired direction (increasing or decreasing). Attacking and defending all measurements are impossible for the attacker and defender, respectively. This situation is modeled as a zero–sum game between the attacker and defender. The game deﬁnes the proportion of times that the attacker and defender like to attack and defend different measurements, respectively. From the simulation results based on the PJM 5-Bus test system, we can show the effectiveness and properties of the studied game.
I. I NTRODUCTION Recently, power systems are becoming more and more sophisticated in the structure and conﬁguration because of the increasing in electricity demand and the limited energy resources. Traditional power grids are commonly used to carry power from a few central generators to a large number of customers. In contrast, the new-generation of electricity grid that is also known as the smart grid uses bidirectional ﬂows of electricity and information to deliver power in more efﬁcient ways responding to wide ranging conditions and events  (Fig. 1). Online monitoring of smart grid is important for control centers in different decision making processes. State estimation (SE) is a key function in building real-time models of electricity networks in Energy Management Centers (EMCs) . State estimators provide precise and efﬁcient observations of operational constraints to identify the current operating state of the system in quantities such as transmission line loadings or bus voltage magnitudes. Accuracy of state estimation can be affected by bad data during the measuring process. Measurements may contain errors due to the various reasons such as random errors, incorrect topology information and injection of bad data by attackers. By integrating more advanced cyber technologies into the energy management system (EMS), cyber-attacks can cause major technical problems such as blackouts in power systems1 , . The attacks also can be designed to the attacker’s ﬁnancial beneﬁt at the expense of the general consumer’s net cost of electricity , . attack involves a cyber attack against breakers in a generating unit. This experiment shows the abilities of cyber attackers in taking control over breakers and consequently, it reveals the technical problems of this attack for the power grid . 1 Aurora
In this paper, we consider the case wherein the attacker uses cyber attack against electricity prices. We show that the attacker observes the results of the day–ahead market and changes the estimated transmitted power in order to change the congestion2 level, resulting in a proﬁt. On the other hand, the defender tries to defend the accuracy of network measurements. Since the attacker and defender are not able to attack and defend all measurements, they will compete to increase and decrease the injected false data, respectively. This behavior is modeled by a two-person zero-sum strategic game where the players try to ﬁnd the Nash equilibrium and maximize their proﬁts. The results of simulations on the PJM 5-Bus test system show the effectiveness of attack on the prices of electricity on the real–time market. The remainder of this paper is organized as follows: The literature survey is provided in...