Fault current interruption analysis and development of a power semiconductor switch for a medium-voltage DC hybrid circuit breaker

Qawasmi, Ala; de Doncker, Rik W. (Thesis advisor); Bhattacharya, Subhashish (Thesis advisor)

1. Auflage. - Aachen : E.ON Energy Research Center, RWTH Aachen University (2021, 2022)
Book, Dissertation / PhD Thesis

In: E.ON Energy Research Center ; PGS, Power Generation and Storage Systems 98
Page(s)/Article-Nr.: 1 Online-Ressource : Illustrationen, Diagramme

Dissertation, RWTH Aachen University, 2021


The integration of distributed renewable power generation, electromobility and small storage systems presents a challenge for the distribution network. The multiterminal medium-voltage direct current (MVDC) grid technology promises an efficient and flexible integration and power distribution. Thus, fast isolation of faulty network segments in MVDC grids is a key requirement that ensures an uninterrupted power ow and guarantees the safety of the system components. This thesis analyzes fault currents in MVDC distribution networks and the contribution of the different grid components to these fault currents. It investigates different circuit breaker technologies and their capability to interrupt fault currents. The thesis compares their applicability, size, and performance. The hybrid circuit breaker (HCB) technology promises fast fault current interruption besides low conduction loss during normal operation. The thesis proposes a new power semiconductor switch specially designed for the HCB. The switch is based on the gate turn-off thyristor, which has a high current interruption capability. It employs the thyristors' high current interruption capability while using a small package and a reduced number of components to guarantee high reliability. The thesis presents a multi-physics design approach of the switch, and investigates its mechanical, electrical and thermal limitations. It discusses their effect on the device's operation and current interruption capacity. Besides, the dissertation describes the structure of the low power devices, required for the switch and HCB function, and their operation. Experimental tests demonstrate the switch's operation and performance and validate its application in the HCB. The switch's operation is verified and analyzed through tests of different prototypes. In conclusion, the performance, limitations, and improvement opportunities of the power semiconductor switch are indicated.