Simulation of protection functions in LV shipboard electrical power systems

The basic function of a shipboard electric power systems is to supply all consumers, both essential and non-essential, with electrical energy, as economically as possible and with an acceptable degree of quality. A shipboard electrical power system comprises three principal subsystems: generation (naval power plant-island mode plant), distribution and protection and automation. During operation all these subsystems may be affected by faults. In this aim all electrical installations on shipboards are to be protected against over-currents due to short- circuits or accidental overloads. The new ABB air circuit-breakers Emax 2 and Tmax T series can be used both as main circuit-breaker in low voltage generation and distribution systems. In addition to protection, the new air ABB circuit-breakers offer possibility of communication which are particularly suitable for automation, control, measurements, grid analysis, and energy savings. ABB Relays are high-performance electronic units for these circuit breakers. Their basic function is to monitor and protect the electric systems against fault current. The units also includes: measuring, data storage, communication, self-test, load control and zone selectivity functions for these circuit-breakers. This paper presents the analysis of protections and simulates how to trigger protections within shipboard power systems.