A Survey on Home Energy Management <s> A. ATTACKS ON SMART GRID <s> This paper presents new results on the applications of reachability methods and computational tools to a twoarea power system in the case of a cyber attack. In the VIKING research project a novel concept to assess the vulnerabilities introduced by the interaction between the IT infrastructure and power systems is proposed. Here we develop a new framework and define a systematic methodology, based on reachability, for identifying the impact that an intrusion might have in the Automatic Generation Control loop, which regulates the frequency and the power exchange between the controlled areas. The numerical results reveal the weaknesses of the system and indicate possible policies that an attacker could use to disturb it. <s> BIB001 </s> A Survey on Home Energy Management <s> A. ATTACKS ON SMART GRID <s> The advanced metering infrastructure (AMI) is a crucial component of the smart grid, replacing traditional analog devices with computerized smart meters. Smart meters have not only allowed for efficient management of many end-users, but also have made AMI an attractive target for remote exploits and local physical tampering with the end goal of stealing energy. While smart meters posses multiple sensors and data sources that can indicate energy theft, in practice, the individual methods exhibit many false positives. In this paper, we present AMIDS, an AMI intrusion detection system that uses information fusion to combine the sensors and consumption data from a smart meter to more accurately detect energy theft. AMIDS combines meter audit logs of physical and cyber events with consumption data to more accurately model and detect theft-related behavior. Our experimental results on normal and anomalous load profiles show that AMIDS can identify energy theft efforts with high accuracy. Furthermore, AMIDS correctly identified legitimate load profile changes that more elementary analyses classified as malicious. <s> BIB002 </s> A Survey on Home Energy Management <s> A. ATTACKS ON SMART GRID <s> The solutions offered to-date for end-user privacy in smart meter measurements, a well-known challenge in the smart grid, have been tied to specific technologies such as batteries or assumptions on data usage without quantifying the loss of benefit (utility) that results from any such approach. Using tools from information theory and a hidden Markov model for the measurements, a new framework is presented that abstracts both the privacy and the utility requirements of smart meter data. This leads to a novel privacy-utility tradeoff problem with minimal assumptions that is tractable. For a stationary Gaussian model of the electricity load, it is shown that for a desired mean-square distortion (utility) measure between the measured and revealed data, the optimal privacy-preserving solution: i) exploits the presence of high-power but less private appliance spectra as implicit distortion noise, and ii) filters out frequency components with lower power relative to a distortion threshold; this approach encompasses many previously proposed approaches to smart meter privacy. <s> BIB003 </s> A Survey on Home Energy Management <s> A. ATTACKS ON SMART GRID <s> Cyber systems play a critical role in improving the efficiency and reliability of power system operation and ensuring the system remains within safe operating margins. An adversary can inflict severe damage to the underlying physical system by compromising the control and monitoring applications facilitated by the cyber layer. Protection of critical assets from electronic threats has traditionally been done through conventional cyber security measures that involve host-based and network-based security technologies. However, it has been recognized that highly skilled attacks can bypass these security mechanisms to disrupt the smooth operation of control systems. There is a growing need for cyber-attack-resilient control techniques that look beyond traditional cyber defense mechanisms to detect highly skilled attacks. In this paper, we make the following contributions. We first demonstrate the impact of data integrity attacks on Automatic Generation Control (AGC) on power system frequency and electricity market operation. We propose a general framework to the application of attack resilient control to power systems as a composition of smart attack detection and mitigation. Finally, we develop a model-based anomaly detection and attack mitigation algorithm for AGC. We evaluate the detection capability of the proposed anomaly detection algorithm through simulation studies. Our results show that the algorithm is capable of detecting scaling and ramp attacks with low false positive and negative rates. The proposed model-based mitigation algorithm is also efficient in maintaining system frequency within acceptable limits during the attack period. <s> BIB004 </s> A Survey on Home Energy Management <s> A. ATTACKS ON SMART GRID <s> Monitoring and actuation represent critical tasks for electric power utilities to maintain system stability and reliability. As such, the utility is highly dependent on a low latency communication infrastructure for receiving and transmitting measurement and control data to make accurate decisions. This dependency, however, can be exploited by an adversary to disrupt the integrity of the grid. We demonstrate that Denial of Service (DoS) attacks, even if perpetrated on a subset of cyber communication nodes, has the potential to succeed in disrupting the overall grid. One countermeasure to DoS attacks is enabling cyber elements to distributively reconfigure the system's routing topology so that malicious nodes are isolated. We propose a collaborative reputation-based topology configuration scheme and through game theoretic principles we prove that a low-latency Nash Equilibrium routing topology always exists for the system. Numerical results indicate that during an attack on a subset of cyber nodes, the proposed algorithm effectively enables the remaining nodes to converge quickly to an equilibrium topology and maintain dynamical stability in the specific instance of an islanded microgrid system. <s> BIB005 </s> A Survey on Home Energy Management <s> A. ATTACKS ON SMART GRID <s> In a cascading power transmission outage, component outages propagate nonlocally; after one component outages, the next failure may be very distant, both topologically and geographically. As a result, simple models of topological contagion do not accurately represent the propagation of cascades in power systems. However, cascading power outages do follow patterns, some of which are useful in understanding and reducing blackout risk. This paper describes a method by which the data from many cascading failure simulations can be transformed into a graph-based model of influences that provides actionable information about the many ways that cascades propagate in a particular system. The resulting “influence graph” model is Markovian, in that component outage probabilities depend only on the outages that occurred in the prior generation. To validate the model, we compare the distribution of cascade sizes resulting from $n-2$ contingencies in a 2896 branch test case to cascade sizes in the influence graph. The two distributions are remarkably similar. In addition, we derive an equation with which one can quickly identify modifications to the proposed system that will substantially reduce cascade propagation. With this equation, one can quickly identify critical components that can be improved to substantially reduce the risk of large cascading blackouts. <s> BIB006 </s> A Survey on Home Energy Management <s> A. ATTACKS ON SMART GRID <s> The smart grid is arguably one of the most complex cyber-physical systems (CPS). Complex security challenges have been revealed in both the physical and the cyber parts of the smart grid, and an integrative analysis on the cyber-physical (CP) security is emerging. This paper provides a comprehensive and systematic review of the critical attack threats and defence strategies in the smart grid. We start this survey with an overview of the smart grid security from the CP perspective, and then focuses on prominent CP attack schemes with significant impact on the smart grid operation and corresponding defense solutions. With an in-depth review of the attacks and defences, we then discuss the opportunities and challenges along the smart grid CP security. We hope this paper raises awareness of the CP attack threats and defence strategies in complex CPS-based infrastructures such as the smart grid and inspires research effort toward the development of secure and resilient CP infrastructures. <s> BIB007 </s> A Survey on Home Energy Management <s> A. ATTACKS ON SMART GRID <s> Advanced Metering Infrastructure (AMI) is the core component in a smart grid that exhibits a highly complex network configuration. AMI shares information about consumption, outages, and electricity rates reliably and efficiently by bidirectional communication between smart meters and utilities. However, the numerous smart meters being connected through mesh networks open new opportunities for attackers to interfere with communications and compromise utilities assets or steal customers private information.In this paper, we present a new DoS attack, called puppet attack, which can result in denial of service in AMI network. The intruder can select any normal node as a puppet node and send attack packets to this puppet node. When the puppet node receives these attack packets, this node will be controlled by the attacker and flood more packets so as to exhaust the network communication bandwidth and node energy. Simulation results show that puppet attack is a serious and packet deliver rate goes down to 20-10%. After analyzing the puppet attack, we propose the detection and prevention mechanism. Simulations show that puppet attack causes the same damage as a flooding attack and the proposed method can prevent the puppet attack efficiently. <s> BIB008
Smart grid attack schemes can be grouped into the following subcategories BIB007 : (a) Generation systems -power generators are managed by automatic generation control (AGC) systems, which employ load-frequency control (LFC) and distribution mechanisms to maintain a desirable generation-supply balance with minimum operational costs. False data injection BIB004 , BIB005 and control signal adulteration BIB001 attacks are commonly aimed to damage generators and power lines, being responsible for interrupting power supply and for power swinging. (b) Transmission systems -interdiction of transmission lines and tripping of transformers, generators, buses or substations are common attack vectors carried out by manipulating commands or due to false data injection BIB007 . Alternatively, attackers can gain unauthorised access to system topology information, identifying strategically vulnerable components as future attack targets BIB006 . (c) Customer-side -customer-side equipments generally lack built-in security features, which attackers may take advantage for energy theft BIB002 , information leakage BIB003 and denial-of-service BIB008 attacks. It should be noted that, even though isolated single-building attacks have a very insignificant impact on grid stability, synchronised attacks over large clusters of consumers can severely damage transmission lines and cause large-scale power outages BIB007 . (d) Electricity market -this kind of attack exploits higher prices in dynamic pricing schemes, such as RTP, during periods of higher demand stress, for illegal profit based on the price margin between on-peak and off-peak tariffs. The scheme is propped up on buying additional electricity at lower prices to be sold at higher rates during a subsequent attack BIB007 . VOLUME 8, 2020