Research on meshed MVDC (Medium Voltage Direct Current) grids has significantly increased in recent years due to the need to address the issues of traditional radial AC (Alternating Current) distribution networks. In a meshed DC grid, fault currents must be controlled to protect power converters from potential damage and provide a reasonable current-time ratio to properly and successfully activate the protection systems.

In this context, reliable, fast, and efficient MVDC interruption devices become necessary. Traditional mechanical breakers do not perform current-limiting functions and are generally quite expensive for distribution network applications compared to their AC counterparts.

Furthermore, in meshed networks, fault interruption times become crucial compared to traditional radial distribution systems. This is essential to increase selectivity and maximize overall system reliability. For these reasons, this research has developed, sized, and simulated a new solid-state MVDC breaker model, integrated with a fault current limiting function. The device was then tested using real-time Control Hardware in the Loop (CHIL) simulations.

The activity is structured as follows: it begins with an overview of the device’s structure and operating principle, followed by the sizing of components to achieve the expected performance. The control and command structure of the device is then described, and preliminary Matlab/Simulink simulation results are presented. After detailing the CHIL equipment and test setup, real-time CHIL simulation results are reported. Finally, the results from preliminary simulations and CHIL tests are compared and discussed, leading to the conclusions of the study.