Active fault management for microgrids

Fault management is critical for efficiently supporting the increasing microgrids' penetration in distribution networks but remains an open problem. No existing ride through methods can ride through symmetrical and asymmetrical faults without increasing the fault current magnitude, meanwhile balancing microgrid power and eliminating double frequency ripples in microgrid inverters. The paper bridges this gap by contributing a novel active fault management (AFM) method. The new contributions include: 1) the development of a new conceptual AFM to control multiple variables during voltage dips; 2) the optimization-based AFM to coordinate different objectives according to a guidance and 3) a combined optimization and feedback control, during which optimization method provides the optimal trade-offs among different objectives and the feedback control ensures accurate realization of chosen operation points. Simulations with different types of faults prove that the developed AFM can achieve better trade-offs and coordination among various control objectives in comparison to the conventional ride through method.