In the application process of distributed feeder automation (FA) that is based on peer-to-peer exchange of measurement and control data between smart terminal units (STUs), there is an urgent need for standardized communication interaction and necessary security protection. This paper proposes an IEC 61850 communication mapping scheme using built-in secure extensible messaging and presence protocol (XMPP) and the generic object oriented substation event based on the user datagram protocol (GOOSE over UDP) and a security protection scheme based on hash to obtain random subsets (HORS); one-time signature algorithm is used to ensure the communication safety of GOOSE messages. The agent-based distributed FA test system is developed with the STUs. The test results show the scheme can meet the requirements of the quick distributed feeder automation.

In this paper, a tracking control method with thruster fault tolerant control is proposed for unmanned underwater vehicles. First, a cascaded control method is briefly introduced for the robust tracking control. Then it deals with the tracking control problem when thrusters have faults. For the cases that thrusters are completely malfunctioned, different control strategies are used to reallocate the thruster forces. Weighted pseudo inverse and quantum particle swarm optimization (QPSO) is introduced to do the hybrid fault tolerant control for different cases. To perform an appropriate control reallocation, an infinity norm cost function is introduced in QPSO as the optimization criterion to find the solution of the control reallocation problem within the limits. Compared with the weighted pseudo-inverse method, the QPSO algorithm does not need truncation or scaling to ensure the feasibility of the solution because its particles search for the solution in the feasible space. The proposed controller is implemented in order to evaluate its performance in different faulty situations and the efficiency is demonstrated through simulations results.

In Web2.0, OpenAPIs (such as Google Map, Flickr and Amazon S3) are considered to be among the most important and vital building blocks for the mashups that combine data and services provided by third parties through OpenAPIs, as well as internal data sources owned by users to aggregate user values and promote user innovation. But as a growing number of OpenAPIs are available on the Internet, the developer and user faces the challenge of dynamic complexity in finding and integrating the right set of OpenAPIs. In this paper, we propose a framework to address the problem of self-adaption in the Internet-scale mashups. First, we design a repository for storing OpenAPIs with Multi-granularity and then introduce QoS metrics measuring the potential impact of OpenAPI properties. We further encapsulate different OpenAPIs whose functionality is synonymous, but with different providers, communication protocols, data formats and parameters. Ultimately, we provide a ranking-style algorithm exploiting the encapsulated interface and QoS characteristics to dynamically select the right OpenAPI in runtime. In short, we propose a QoS-based mashup platform that can facilitate the construction of mashup and improve users' experience. The process is transparent and automatic to the users'. Experimental evaluation demonstrates the effectiveness of our approach.

Distributed control has good real-time performance and can better meet the control requirements of active distribution networks with a large number of distributed generations. Some distributed applications require real-time feeder topology to achieve control. In this paper, the demand for distributed control applications for feeder real-time topology is analyzed. Based on IEC 61850 modeling method, a new cell topology logic node and a new topology slice node are built to express feeder topology. Using the topology information of smart terminal unit (STU) configuration and the current status information of switchgear, based on the depth-first search, the feeder real-time topology identification can be realized, which meets the application requirements of distributed control. The study case verified the effectiveness of the method.

Low-voltage distribution lines lack efficient monitoring. With the massive proliferation of distributed energy resource supply, it is necessary to establish an effective monitoring system for low-voltage distribution lines to ensure the electrical safety and continuity of power supply services. This paper proposes monitoring system for low-voltage distribution lines based on the Internet of things (IoT) technology. An IoT based monitoring system contains a large number of low-voltage monitoring terminals, different manufacturers, and different types of terminal equipment to solve the interconnection problem of information interaction. This paper first analyzes the terminal functional communication requirements based on IEC 61850 standards. Further, the information models required by the electrical volume collection and non-electric quantity collection functions are studied. The information modeling for different types of monitoring terminal equipment is presented and thus provide the configuration suggestions. The monitoring terminal based on the information model developed in this paper is applied in a university campus to realize the monitoring of low-voltage lines and distributed power supply.