Antonio Carrapatoso

A new topology of fast solid-state HVDC circuit breaker for offshore wind integration applications

Emerging new voltage source converter based HVDC applications demand fast short-circuit fault current interruption. Fast dc circuit breakers are identified as the feasible solution to handle the dc fault current. Switching overvoltage across the dc circuit breakers is destructive for the interrupter device and also for the other components of the system. A new topology of fast solid-state circuit breaker for HVDC applications is proposed in this paper. Instead of conventional approaches, a pre-charged capacitor is used for soft switching. Different modes of operation of proposed circuit breaker are analysed and also design process of circuit parameters are described. Finally, simulation results are presented.

Reliable data distribution using multicast groups in industrial systems

The exploitation of multicast technologies leads to an improvement in both the performance and scalability of some distributed applications. Applications needing reliable transference of data in long-lived sessions from one source to multiple receivers are typical in industrial automation. This paper describes a multicast transport protocol designed according to such needs and implemented with good results in a SCADA system. The authors addressed reliability using a NACK-based approach and implemented flow and congestion control based on destination set grouping in order to achieve fairness in the treatment of all receivers even when a link or a host becomes congested.