For accommodating rapidly increasing power demands, power systems are transitioning from analog systems to systems with increasing digital control and communications. Although this modernization brings many far-reaching benefits, the hardware and software newly incorporated into the power systems also incur many vulnerabilities. By taking advantage of these vulnerabilities, adversaries can launch various cyber/physical attacks to tamper with electricity meter readings, i.e., to steal electricity. It is reported that total worldwide annual economic losses caused by electricity theft reached up to almost one hundred billion dollars in recent years. With methods to tamper with meter readings becoming more versatile, secret, and flexible, electricity theft tends to get even more serious in modernized power systems. For preventing adversaries from stealing electricity, researchers have done a lot of works. Although some related surveys on these works exist, they are not updated or just discuss electricity theft in a specific region. This survey aims to gain a comprehensive and in-depth understanding of the electricity theft issue. After investigating how adversaries tamper with meter readings, we systematically survey all existing detection methods up to date, which is classified into machine learning- and measurement mismatch-based methods. Adverse effects and political and socioeconomic factors of electricity theft are also provided. This survey can help relevant researchers to shape future research directions, especially in the area of developing new effective electricity theft detection methods.

In smart grids, various Internet-of-Things-based (IoT-based) components are massively deployed across the power systems. However, most of these IoT-based components have their own vulnerabilities, leveraging which malicious users can launch different cyber/physical attacks to steal electricity. Economic losses caused by electricity theft amount to $96 billion in 2017. Most existing electricity theft detection techniques suffer from either a high deployment cost or a low detection accuracy. To address these concerns, we propose a novel Electricity Theft Detector based upon Convolutional Long Short Term Memory neural networks, called ETD-ConvLSTM. By installing a central observer meter in each community, we can know which communities have malicious users. For these communities, users’ time series of electricity consumptions with temporal correlations are transformed into spatio-temporal sequence data, mainly by constructing a two-dimensional matrix containing both consumptions and consumption differences among several adjacent days. This matrix is then divided into a sequence of sub-matrices, which are then fed into a ConvLSTM network consisting of multiple stacked ConvLSTM layers, with each layer formed by several temporarily concatenated ConvLSTM nodes. When capturing the periodicity in users’ consumption patterns, the ETD-ConvLSTM method considers both global and local knowledge, and hence the detection accuracy improves significantly. Simulations results show that compared with existing state-of-the-art detectors, the proposed ETD-ConvLSTM method can obtain better or comparable performance in terms of detection accuracy, false negative rates and false positive rates within much shorter detection time.

Clustering is an effective method to manage communications in cognitive radio sensor networks (CRSNs). This letter proposes a network stability-aware clustering (NSAC) protocol for CRSNs. Spectrum dynamics and energy consumption are for the first time simultaneously integrated into the protocol design of NSAC. Extensive simulations show that the proposed NSAC protocol obviously outperforms existing methods in the aspects of network stability and energy consumption.

To maintain stable and reliable operations in smart grid, accurate state estimation is of paramount importance. However, synthesized false data injection attacks could wisely circumvent conventional bad data detection mechanisms by introducing arbitrary errors to state estimates to seriously affect the entire power system operation. To defend these attacks, phase measurement units are deployed in advance at various locations to reduce the chance of being attacked. However, when the budget of placement is not large enough so that the whole system cannot be covered by phase measurement units, the existing phase measurement unit placement algorithms based on greedy strategies are insufficient in some weak locations due to the nature of greedy strategies. In this paper, we propose a new hybrid attack, which can easily used by attackers to attack the buses with less connectivity and impose adverse impacts to state estimation with a low attack cost so that existing defenses based on greedy strategies become invalid. We future propose a pre-deployment phase measurement unit greedy algorithm for this new attack in which the most vulnerable buses are first protected, and then a greedy-based algorithm is used to deploy other phase measurement units until the whole system is observable. Experimental results on various IEEE standard systems demonstrate the effectiveness of our schemes.

State estimation plays a vital role to ensure safe and reliable operations in smart grid. Intelligent attackers can carefully design a destructive and stealthy false data injection attack (FDIA) sequence such that commonly used weighted least squares estimator combined with residual-based detection method is vulnerable to the FDIA. To effectively defend against an FDIA, in this paper, we propose a robust deviation-based detection method, in which an additional Kalman filter is introduced while retaining the original weighted least squares estimator, so that there are two state estimators. Moreover, an exponential weighting function is also applied to the introduced Kalman filter in our proposed method. When an FDIA occurs, the estimation results of weighted least squares estimator depend only on meter measurements at each time slot, but there is an adjustment process of estimated states for the Kalman filter based on historical states' transitions. Meanwhile, based on the exponential weighting function, estimated measurements in the Kalman filter can be adaptively suppressed for different attack strengths of FDIAs, and then the difference of the results of these two estimators increases. Subsequently, FDIAs can be effectively detected by checking the deviation of estimated measurements about the two estimators with a detection threshold. Experimental results validate the effectiveness of the proposed detection method against FDIAs. The impact of different attack strengths and noise on detection performance is also evaluated and analyzed.