Shunt Compensation for DC Microgrid Stabilization Utilizing T-Type Modular Dc Circuit Breaker

Power electronics converters based loads in dc microgrids are often constant power loads (CPLs). They could destabilize the dc grid during voltage transients or load power changes due to their negative impedance characteristics. The newly proposed T-Type Modular Dc Circuit Breaker (T-Breaker) integrates current breaking, current limiting and grid transient compensation functions into one device thanks to its integrated energy storage and modular multilevel converter structures. Much like the current and voltage compensations in ac systems, the T-Breaker can help the ride-through of grid transients by implementing shunt (current) and series (voltage) compensations. This paper focuses on the shunt compensation function of the T-Breaker. Related system modeling, small signal analysis, large signal analysis, simulation and experimental validations are presented in the paper.