Biblio

The interaction between the transmission system of doubly-fed wind farms and the power grid and the stability of the system have always been widely concerned at home and abroad. In recent years, wind farms have basically installed static var generator (SVG) to improve voltage stability. Therefore, this paper mainly studies the subsynchronous oscillation (SSO) problem in the grid-connected grid-connected doubly-fed wind farm with static var generators. Firstly based on impedance analysis, the sequence impedance model of the doubly-fed induction generator and the static var generator is established by the method. Then, based on the stability criterion of Bode plot and time domain simulation, the influence of the access of the static var generator on the SSO of the system is analyzed. Finally, the sensitivity analysis of the main parameters of the doubly-fed induction generator and the static var generator is carried out. The results show that the highest sensitivity is the proportional gain parameter of the doubly-fed induction generator current inner loop, and its value should be reduced to reduce the risk of SSO of the system.

Affected by the inherent ideas like "Focus on Function Realization, Despise Security Protection", there are lots of hidden threats in the industrial control system of wind farms (ICS-WF), such as unreasonable IP configuration, failure in virus detection and killing, which are prone to illegal invasion and attack from the cyberspace. Those unexpected unauthorized accesses are quite harmful for the stable operation of the wind farms and regional power grid. Therefore, by investigating the current security situation and needs of ICS-WF, analyzing the characteristics of ICS-WF’s architecture and internal communication, and integrating the ideas of the classified protection of cybersecurity, this paper proposes a new customized cybersecurity strategy for ICS-WF based on the barrel theory. We also introduce an new anomalous intrusion detection technology for ICS-WF, which is developed based on statistical models of wind farm network characteristics. Finally, combined all these work with the network security offense and defense drill in the industrial control safety simulation laboratory of wind farms, this research formulates a three-dimensional comprehensive protection solution for ICS-WF, which significantly improves the cybersecurity level of ICS-WF.

Industry 4.0 or also known as the fourth industrial revolution poses a great cybersecurity risk for Supervisory control and data acquisition (SCADA) systems. Nowadays, lots of enterprises have turned into renewable energy and are changing the energy dependency to be on wind power. The SCADA systems are often vulnerable against different kinds of cyberattacks and thus allowing intruders to successfully and intrude exfiltrate different wind farm SCADA systems. During our research a future concept testbed of a wind farm SCADA system is going to be introduced. The already existing real-world vulnerabilities that are identified are later on going to be demonstrated against the test SCADA wind farm system.

The massive integration of Renewable Energy Sources (RES) into power systems is a major challenge but it also provides new opportunities for network operation. For example, with a large amount of RES available at HV subtransmission level, it is possible to exploit them as controlling resources in islanding conditions. Thus, a procedure for off-line evaluation of islanded operation feasibility in the presence of RES is proposed. The method finds which generators and loads remain connected after islanding to balance the island's real power maximizing the amount of supplied load and assuring the network's long-term security. For each possible islanding event, the set of optimal control actions (load/generation shedding) to apply in case of actual islanding, is found. The procedure is formulated as a Mixed Integer Non-Linear Problem (MINLP) and is solved using Genetic Algorithms (GAs). Results, including dynamic simulations, are shown for a representative HV subtransmission grid.

The tremendous advances in information and communications technology (ICT), as well as the embedded systems, have been led to the emergence of the novel concept of the internet of things (IoT). Enjoying IoT-based technologies, many objects and components can be connected to each other through the internet or other modern communicational platforms. Embedded systems which are computing machines for special purposes like those utilized in high-tech devices, smart buildings, aircraft, and vehicles including advanced controllers, sensors, and meters with the ability of information exchange using IT infrastructures. The phrase "internet", in this context, does not exclusively refer to the World Wide Web rather than any type of server-based or peer-to-peer networks. In this study, the application of IoT in smart grids is addressed. Hence, at first, an introduction to the necessity of deployment of IoT in smart grids is presented. Afterwards, the applications of IoT in three levels of generation, transmission, and distribution is proposed. The generation level is composed of applications of IoT in renewable energy resources, wind and solar in particular, thermal generation, and energy storage facilities. The deployment of IoT in transmission level deals with congestion management in power system and guarantees the security of the system. In the distribution level, the implications of IoT in active distribution networks, smart cities, microgrids, smart buildings, and industrial sector are evaluated.

In recent years, there has been a significant increase in wind power penetration into the power system. As a result, the behavior of the power system has become more dependent on wind power behavior. Supervisory control and data acquisition (SCADA) systems responsible for monitoring and controlling wind farms often have vulnerabilities that make them susceptible to cyberattacks. These vulnerabilities allow attackers to exploit and intrude in the wind farm SCADA system. In this paper, a cyber-physical system (CPS) model for the information and communication technology (ICT) model of the wind farm SCADA system integrated with SCADA of the power system is proposed. Cybersecurity of this wind farm SCADA system is discussed. Proposed cyberattack scenarios on the system are modeled and the impact of these cyberattacks on the behavior of the power systems on the IEEE 9-bus modified system is investigated. Finally, an anomaly attack detection algorithm is proposed to stop the attack of tripping of all wind farms. Case studies validate the performance of the proposed CPS model of the test system and the attack detection algorithm.

With the development of smart grid, information and energy integrate deeply. For remote monitoring and cluster management, SCADA system of wind farm should be connected to Internet. However, communication security and operation risk put forward a challenge to data network of the wind farm. To address this problem, an active security defense strategy combined whitelist and security situation assessment is proposed. Firstly, the whitelist is designed by analyzing the legitimate packet of Modbus on communication of SCADA servers and PLCs. Then Knowledge Automation is applied to establish the Decision Requirements Diagram (DRD) for wind farm security. The D-S evidence theory is adopted to assess operation situation of wind farm and it together with whitelist offer the security decision for wind turbine. This strategy helps to eliminate the wind farm owners' security concerns of data networking, and improves the integrity of the cyber security defense for wind farm.