Correct operation of the future multi-terminal and multi-level MVDC networks requires an adequate study of the protection systems to cope with failure events and ensure the service continuity for users. In this research context, the integration of a static breaker and a fault current limitation device in different multiterminal and multilevel MVDC network configurations is evaluated.

The activity includes the development of a static limitation and breaking device to allow the bipolar interruption of line currents. Such concept allows the proper integration of static devices in the meshed network structures considered in the report.
The study is conducted through software and Control Hardware In the Loop simulations of the developed network models, as well as an analysis of static protection devices positioning.

Positioning of static protection devices into the network is considered, as well as operational scenarios with MVDC multiterminal meshed networks and configurations based on multiport network converters.
The analysis focuses on bipolar static breaker model test, including control logic validation and its implementation into a physical hardware. Simulations address extinction of permanent pole-to-pole fault overcurrent.

In conclusion, for all analyzed cases, it is shown that the selection and disconnection of a faulty branch can be achieved without an external supervision and control system, by using a series of maximum current protections. The same control structure can be used, with limited modifications, both for the bipolar static device scheme as well as the unipolar version.

The Report is available on the Italian site