The safety and security of load frequency control (LFC) system are menaced by cyber attacks and physical attacks. Sophisticated attackers can launch cyber-physical attacks (CPAs), in which cyber attacks are used to increase the impacts of physical attacks by sending wrong instructions to the LFC controller. Considering that parameters of cyber attacks in CPAs may be either fixed or variable, a novel detection scheme is designed against two potential CPAs on an LFC system, namely fixed cyber-physical attacks (FCPAs) and variable cyber-physical attacks (VCPAs), respectively. As for FCPAs, dynamic characteristics of Area Control Error (ACE) are utilized to detect the compromised data. Compared with FCPAs, VCPAs are more deceptive. A relation-based (RB) feature extraction method is introduced to distinguish the signals compromised by VCPAs from the normal ones. A detection model that does not require compromised samples is developed with the aid of support vector domain description. In the end, a comprehensive detection scheme is designed to detect both FCPAs and VCPAs on the LFC system.

Wind power is volatile and uncertain, which makes it difficult to establish an accurate prediction model. How to quantitatively describe the distribution of wind power output is the focus of this paper. First, it is assumed that wind speed is a random variable that satisfies the normal distribution. Secondly, based on the nonlinear relationship between wind speed and wind power, the distribution model of wind power prediction is established from the viewpoint of the physical mechanism. The proposed model successfully shows the complex characteristics of the wind power prediction distribution. The results show that the distribution of wind power prediction varies significantly with the point forecast of the wind speed.

The tie-line bias control (TBC) method has been widely used in the load frequency control (LFC) of multi-area interconnected systems. However, it should be questioned whether the conventional TBC can still apply to LFC when considering the complication of structures of power systems. LFC, in essence, is to stabilize system frequency/tie-line power by controlling controlled outputs’ area control error (ACE). In this paper, relations between LFC control variables and controlled outputs are expressed as a system of equations, based on which an exemplary ring network is studied. Sufficient and necessary conditions for TBC applicability is presented, and a novel LFC mode is proposed for a general ring network where TBC cannot work. Finally, TBC applicability to multi-area systems with general topology is studied, and a general LFC mode is proposed for systems where TBC is not definitely applicable, thus rendering routines that may guide LFC design of future power systems with more complex topologies.

In this paper, partial synchronization of the distributed parameter system (DPS) with time delay is considered via Galerkin's method and the fuzzy control. First, based on Galerkin's method, the dynamics of master DPS and slave DPS can be described by low-order ordinary differential equations (ODEs). Then the low-order functional ODEs are used as the basis for the design of the fuzzy controller to ensure the synchronization between the two low-order ODEs; moreover, when the slow system of master DPS and the slow system of slave DPS are synchronized, the error between master DPS and slave DPS is bounded. Some criteria are derived for stabilization and linear matrix inequality design approach is developed. The effectiveness of the proposed controller design methodology is finally demonstrated through numerical simulation.

Renewable energy has the characteristics of low carbon and environmental protection compared to traditional water and thermal power, but it also has the intermittency and uncertainty that traditional water and thermal power does not have. These characteristics make the inertia of the power system increase, which greatly affects the frequency stability of the grid. To solve such problems, the participation of demand-side resources (DSRs) in the dispatch of power systems has become a viable solution.However, unlike generation-side resources, DSRs have their own unique characteristics. In this paper, by taking into account a load frequency control system (LFC) with intermittent demand-side resources, the robust H∞ load frequency control problem are discussed in detail.A robust controller to coordinate the load side with the resource side is introduced. A critical stability criterion and robust performance evaluation of the new LFC system was carried out. Finally, simulation results based on the new LFC system are provided to demonstrate that the proposed control strategy can effectively improve the stability and robustness of the grid under large disturbances, thus allowing the grid frequency to return to the reference value.