Design and Validation of a Grid-Integrable Medium-Voltage Hybrid DC Circuit Breaker

Abdul Basit Mirza
Stony Brook University, 2022
Read Here  

Abstract: Recently, Hybrid Circuit Breakers (HCB) have become optimum choice for protection in Medium Voltage Direct Current (MVDC) applications. They combine the advantages of less conduction loss in Electromechanical Circuit Breakers (ECB) and fast fault interruption in Solid State Circuit Breakers (SSCB). An MVDC Hybrid Circuit Breaker (HCB) is proposed that consists of an electro-mechanical switch (EMS) in series with a Voltage Injector Building Block (VIBB). The VIBB-HCB does not employ any semiconductor devices in the main DC line. The VIBB utilizes an E-core-based integrated magnetic structure for injection purposes. The core is unbiased during regular operation, which does not affect system response or add more inductance in the main DC line. Further, the injection circuit is isolated from the main circuit. Hence, any surge or fault current does not impact the injection circuit. The injection circuit comprises a SiC-based full bridge auxiliary converter, which provides fast (µs range) bidirectional fault-clearing capability. Moreover, the EMS is opened under zero voltage and zero current, which increases EMS reliability and lifetime. Lastly, the design does not require bulky high-rating energy absorption components such as varistors due minuscule post-fault interruption residual energy. A detailed design procedure is derived and validated through Finite Element Analysis using ANSYS Maxwell Transient solver. This is followed by experimental verification on a scaled-down hardware prototype.

Recommended citation (BibTex):

@phdthesis{Mirza2022, 
 author = {Mirza, Abdul Basit}, 
 school = {Stony Brook University}, 
 title = {Design and Validation of a Grid-Integrable Medium-Voltage Hybrid DC Circuit Breaker}, 
 year = {2022} 
}